Macros in Nim - Tutorial¶
# nim c -d:release --nimcache:lixo -o:rd.x rd.nim
import os, strutils, sequtils, sugar
proc avg(xs: seq[float]): float =
result= 0.0
var n= 0.0
for x in xs:
result= result + x
n= n+1.0
result= result/n
proc main() =
if paramCount() < 1: quit("Usage: " & paramStr(0) & " <filename.data>")
let s = readFile(paramStr(1)).splitWhitespace.map(x => x.parseFloat)
echo "Sum= ", s.foldl(a + b), " / Average= ", avg(s)
main()
_processfile figure:: Read and process a file
Let us find out how many students graduate from
medical schools in California. The grad.data
file gives the number of graduates from each
school. The rd.nim program prints the addition
and the average. Here is how to compile and run
the program of listing :ref:processfile –
src> nim c -o:rd.x -d:release rd.nim # Compile
src> cat nums.data # Check the data
190 45 23 34 89 96 78
97 14 17 54 345 3 42
src> ./rd.x nums.data # Run the program
Sum= 1127.0 / Average= 80.5
The predicate paramCount() < 1 checks whether the file name is
present on the command line. If it is not, the program quits with
a request for the file name. In the snippet below, taken from the
application @readfile, the paramStr(0) string contains the
application name.
if paramCount() < 1:
quit("Usage: " & paramStr(0) & " <filename.data>")
The local variable s receives the result of a sequence of
operations on the file contents. The readFile(paramStr(1))
operation reads the file whose name is on the command line.
The nums.data file contains space separated numbers that
.splitWhitespace parses and produces a sequence of strings.
Finally, map(x => x.parseFloat) transforms this sequence
into floating point numbers that foldl(a+b) adds up.
The avg(xs: seq[float]) sums the floating point numbers
into the result variable and calculates the length of
the sequence into n. The average is result/n.
{width=250px}
The first computer was constructed by Konrad Zuse, a German civil engineer, and his assistant, Ms. Ursula Walk, née Hebekeuser. Ancient computers, like those of Zuse and Walk, were based on relays. These are bulky electrical devices, typically incorporating an electromagnet, which is activated by a current in one circuit to turn on or off another circuit. Computers made of such a contrivance were enormous, slow, and unreliable. Therefore, on September 9th, 1945, a moth flew into one of the relays of the Harvard Mark II computer and jammed it. From that time on, bug became the standard word to indicate an error that prevents a computer from working as intended.
Due to bugs, compilers of languages like Nim and Haskell frequently return error messages, instead of generating code and running the corresponding programs. The Steel Bank Common Lisp language does not interrupt code generation when the compiler spots a bug, all the same it does issue warnings that help find the problem before the embarassment of failure being manifest on the client’s terminal.
Comma separated values¶
# nim c -d:release -o:csv.x --nimcache:lixo csv.nim
import os, strutils, sequtils, sugar
proc main() =
if paramCount() < 1: quit("Usage: " & paramStr(0) & "fname.data")
let
s = readFile(paramStr(1)).split(Whitespace+{','})
xs= s.filter(x => x.len > 0).map(x => x.parseFloat)
echo "Average= ", xs.foldl(a+b)/float(xs.len)
main()
#[
Compile: nim c -d:release -o:csv.x --nimcache:lixo csv.nim
src> cat csv.data
190, 180, 170, 160, 120, 100
100,90
src> ./csv.x csv.data
Average= 138.75
]#
The program above calculate the average of comma separated values.
Everything that comes between #[ and ]# is comments. Therefore,
the comments are giving an example of how to compile and use the
program. Text that comes after # and the end of line is a comment
as well. This second kind of comment is used is very common in shell
commands.
The split(Whitespace+{','}) operation splits a string with
values that can be separated by any combination of chars that
belong to the Whitespace+{','} set. Since split produces
empty "" strings, the program applies filter(x => x.len > 0)
to the result, in order to eliminate zero-length strings from
the sequence.
Iterators¶
# nim c -d:release -o:ird.x --nimcache:lixo ird.nim
import os, strutils
iterator valid[T](a: seq[T]): T=
for x in a:
if x.len != 0: yield x
proc avg(xs: seq[string]): float =
result= 0.0
var n= 0.0
for x in valid(xs):
n= n+1
result= result+x.parseFloat
result= result/n
proc main() =
if paramCount() < 1: quit("Usage: " & paramStr(0) & " fname")
let
s = readFile(paramStr(1)).split(Whitespace+{','})
echo avg(s)
main()
#[
src> nim c -o:ird.x -d:release --nimcache:./lixo ird.nim
src> ./ird.x csv.data
138.75
]#
In the procedure that reads a file and splits it
into a sequence of int, the split function
generates empty strings at the end of the file
and possibly at the end of each line as well.
Therefore, I designed an iterator that feeds
a for-loop with valid strings that can be
parsed to floats, which one can use to calculate
the average of a sequence of values.
In Nim, iterators are as easy to design as normal
functions. In fact, iterators are functions that
produce values more than once. They are defined like
procedures, but the keyword iterator replaces
the keyword proc that defines procedures. Another
difference between iterators and functions is that
an iterator uses the keyword yield, instead of
the keyword return to produce a value. In general,
iterators are used to feed a for-loop with a sequence
of values. After yielding a value, the iterator can
resume the computation to produce the next value. In
the example, the iterator valid yields a sequence of
strings that can be parsed to produce floating point
numbers.
Exceptions¶
# nim c -d:release -o:xrd.x rd.nim
import os, strutils, sequtils, sugar
proc main() =
proc avg(xs: seq[string]): float=
var sm, n = 0.0
for i, x in xs:
try:
sm = sm + x.strip.parseFloat
n= n + 1.0
except: discard
finally: result= sm/n
if paramCount() < 1: quit("Usage: " & paramStr(0) & " filename")
let xs = readFile(paramStr(1)).split(Whitespace+{','})
echo avg(xs)
main()
You will find exceptions in many languages, therefore I
believe that the program above will not pose difficulties.
The avg procedure does not try to eliminate invalid strings
from the sequence. Since the program is not sure that the
string represents a valid floating point number, it tries
to parse it. If the avg procedure fails to parse a string,
the error is captured in an exception section and discarded.
Let us compile and test it:
› nim c -o:excrd.x -d:release --nimcache:del --hints:off excrd.nim
~/nim/tutorial/src
› ./excrd.x csv.data
138.75
I defined the avg procedure inside the main procedure,
just to demonstrate that this is possible. The procedure strip
eliminates blanks around the string, before parsing it to floating
point numbers. This is not strictly necessary, but I did it just to
be on the safe side.
Ready¶
If you installed Nim and tested the programs on the previous pages of this tutorial, you are ready for action. Listing @rpn shows an implementation of an rpn calculator.
# nim c -d:release -o:rpn.x --nimcache:lixo rpn.nim
import os, strutils
type LL= ref object of RootObj
car: float
cdr: LL
template car(a:untyped) : untyped=
if a == nil: quit("Empty stack")
else: a.car
template `>>` (a,b:untyped): untyped= LL(car: a, cdr: b)
proc eval(x: string, s: var LL)=
try: s= x.strip.parseFloat >> s
except:
case x:
of "+": s= (car s) + (car s.cdr) >> s.cdr.cdr
of "x": s= (car s) * (car s.cdr) >> s.cdr.cdr
of "/": s= (car s.cdr) / (car s) >> s.cdr.cdr
of "-": s= (car s.cdr) - (car s) >> s.cdr.cdr
of "neg": s= -(car s) >> s.cdr
else: quit("Error in eval")
var stk: LL = nil
for i in 1 .. paramCount(): eval(paramStr(i), stk)
while stk != nil:
echo stk.car
stk= stk.cdr
(@rpn) Implementation of an rpn calculator
Before trying to understand the program of listing @rpn, let us see how to use it. The program is an emulator of the famous hp calculators.
In pre-algebra, students learn to place arithmetic operators such as (+, -, × and ÷) between their operands; e.g. 345+47. However, when doing sums and subtractions on paper, they stack the operands.
(@sshark) Adding to numbers
Accountants and engineers use the operator itself to separate the result from the operands, instead of drawing a line under the last operand.
Here is the story of a Texan who went on vacation to a beach in Mexico. While he was freely dallying with the local beauties, unbeknownst to him a blackmailer took some rather incriminating photos.
After a week long gallivanting, the Texan returns to his ranch in a small town near Austin. Arriving at his door shortly after is the blackmailer full of bad intentions.
Unaware of any malice, the Texan allows the so called photographer to enter and sit in front of his desk. Without delay, the blackmailer spread out a number of photos on the desk, along with his demands: “For the photo in front of the hotel, that will cost you $25,320.00. Well, the one on the beach that’s got to be $ 56,750.00. Finally, this definitively I can’t let go for less than $136,000.00.”
Once finished with his presentation, the blackmailer snaps up the photos, and looks to the Texan with a sinister grin, awaiting his reply.
Delighted with the selection of pictures, the Texan in an elated voice says: “I thought I would have no recollection of my wonderful time. I want 3 copies of the hotel shot, half a dozen of the beach. And the last one, I need two copies for myself, and please, send one to my ex-wife. Make sure you leave me your contact details; I might need some more.
In order to calculate how much the Texan should pay his supposed blackmailer, his bookkeeper needs to perform the following operations:
3×25320+6×56750+2×136000+136000
Below, you can see how the Texan’s bookkeeper calculates the blackmailer’s payment with the calculator from listing @rpn.
src> ./rpn.x 3 25320 x 6 56750 x + 3 136000 x +
824460.0
Makefile¶
Up to this point, you have used the command line to call the Nim compiler. A better approach to manage compilation is to create a Makefile as the one shown below.
APP=
ifeq ($(APP),)
abort:
@echo Usage: make APP=sourceFile
endif
all:
nim c -o:$(APP).x -d:release --hints:off --nimcache:lixo $(APP).nim
ifeq ($(APP),)
clean:
@echo Usage: make clean APP=file without extension
else
clean:
rm -rf $(APP).x lixo
endif
A Makefile contains rules and recipes. A rule says how to make or remake certain files that are called the rule’s targets. Recipes are written in shell syntax and used to call compilers and commands. In order to distinguish them from rules, one always indents recipes by tabs. If you are using the neovim editor, you can issue a tab by pressing Ctrl-v TAB.
A variable is an id defined in a makefile to represent
a string of text, called value. When you call make to
build a program, you can specify the values of each
variable. For instance, the command below executes the
Makefile of the previous page and compiles the rpn.nim
program.
src> make -f Makefile APP=rpn
In the above example, one has informed the name of the
script to the make-tool through the -f directive,
however this is not necessary if it is called Makefile
or makefile.
When you call make APP=rpn from the command line, the
APP variable receives the rpn value, which will be
expanded in the recipe below:
nim c -o:$(APP).x -d:release --nimcache:lixo $(APP).nim
The result of the expansion will compile the rpn.nim program,
and output the rpn.x executable code.
Linked List¶
Let us understand the program of listing @rpn. A list is a
sequence of connected links, like a chain. In listing @rpn,
links are represented by the LL(car: a, cdr: b) type.
CL-USER> (draw-cons-tree::draw-tree (list 2 4 8 16))
[o|o]---[o|o]---[o|o]---[o|/]
| | | |
2 4 8 16
In the Lisp community, where the idea of linked list gained
momentum, links have two parts, the car field contains the
datum and the cdr field contains the address of the next
link. In order to facilitate creating a connection of two
links, listing @rpn defines the a >> b template, that
assigns the a value to the car field, and the b address
to the cdr field.
The eval(x: string, s: var LL) tries to parse x into
a float pointing number. If it succeeds, the result is
linked to the stk var. If x does not parse, eval
checks whether it is an arithmetic operator through the
except branch of the case-command. Let us suppose that it is
the "+" operator. In this case, "+" fetches its two
arguments from the stack, adds them, and pushes the result
to the stack. The first argument is given by the (car s)
template, and the second argument is given by (car s.cdr).
In the eval(x: string, s:var LL) procedure, s is declared
as var, which means that it can destructively assign values
to the stk var, in the eval(paramStr(i), stk) call.
Macros¶
# make APP=quoteLoop
import macros, strutils, os
macro magicWord(statments: untyped): untyped =
## Designed by Steve Kellock
result = statments
for st in statments:
for node in st:
if node.kind == nnkStrLit:
node.strVal = node.strVal & ", Please."
macro rpt(ix: untyped, cnt: int, statements: untyped)=
quote do:
for `ix` in 1..`cnt`:
`statements`
rpt j, paramStr(1).parseInt :
magicWord:
echo j, "- Give me some bear"
echo "Now"
(@firstmacro) My first macro
Until not long ago, Lisp was the only language that had macros. Not any more. Nim macros will allow you to design new commands for the language.
The first thing to understand about macros is that they don’t belong to the application that you wrote, but are part of the compiler.
Domain Specific Language: DSL¶
A macro rewrites a form from a Domain Specific Language
that is convenient for solving a given problem into
something that the compiler understands. In listing
@firstmacro, before compilation even starts, the macro rpt
will rewrite the macro form…
rpt j, paramStr(1).parseInt :
magicWord:
echo j, "- Give me some bear"
echo "Now"
…into the following stuff:
for j in 1..paramStr(1):
magicWord:
echo j, "- Give me some bear"
echo "Now"
Then, the magicWord macro will add ", Please" to
the echo statements:
for j in 1..paramStr(1):
magicWord:
echo j, "- Give me some bear, Please."
echo "Now, Please."
Only at this point, after the two macros finished their
work, the compilation process will start. The rpt macro
inserts \verb|ix|, \verb|count| and \verb|statements|
into a for-pattern introduced by the quote statement.
The magicWord macro does not works by filling gaps
in a pattern, as the rpt macro. The first step of
compilation transform your program into a branching
data structure known as the Abstract Syntax Tree, or
AST for short. The argument of the AST is a sequence
of statements. The first loop of the magicWord macro
goes through all statement. The second floor examines
all nodes of each statement. If there is a node of
nnkStrLit kind, the macro concatenates ", Please"
to it.
Here below is how the program works:
~/nim/tutorial/src
› make APP=quoteLoop
nim c -o:quoteLoop.x -d:danger --hints:off quoteLoop.nim
~/nim/tutorial/src
› ./quoteLoop.x 2
1- Give me some bear, Please.
Now, Please.
2- Give me some bear, Please.
Now, Please.
Dealing with the AST directly¶
# make APP=rep
# Based on a model by Juan Carlos Paco
import macros
macro iter(i:untyped, c1:untyped,
c2:untyped, stm:untyped): untyped =
result = newNimNode(nnkStmtList) # creates an empty result
var for_loop=
newNimNode(nnkForStmt) # creates a for-loop
for_loop.add(i) # adds index `i` to the for-loop
var rng = # creates a range
newNimNode(nnkInfix).add(ident("..")).add(c1,c2)
for_loop.add(rng) # inserts the range into for_loop
let spc= newLit("- ") # Creates a space string Lit
var wrt = newCall(ident("write"),ident("stdout"), i, spc)
var stmList= newNimNode(nnkStmtList)
stmList.add(wrt)
for s in stm: stmList.add(s)
for_loop.add(stmList)
result.add(for_loop) # insert for_loop into result
iter(i, 0, 3):
echo "Hello, world."
(@AST-tinkering) Tinkering with the AST
Professional programmers, such as the Argentinean Juan Carlos
Paco, don’t use a quote pattern to define a macro, they prefer
to tinker with the AST tree data structure directly.
Listing @AST-tinkering shows how to define a macro to iterate
through a list of commands, that in the example contains only
echo statements.
› make APP=quoteLoop
nim c -o:quoteLoop.x -d:danger --hints:off --nimcache:lixo quoteLoop.nim
CC: stdlib_io.nim
CC: stdlib_system.nim
~/nim/tutorial/src
› ./quoteLoop.x 3
1- Give me some bear, Please.
2- Give me some bear, Please.
3- Give me some bear, Please.
Let us describe the macro of Listing @AST-tinkering.
It starts by creating a nnkForStmt and stores it
in the for_loop variable. The next step is to add
the i index to the for_loop variable. Then it
creates a range for the variable i and adds
it into the for_loop variable. Finally, the
macro creates a stmList (statement list) that
will be repeated in the loop. The macro starts by
inserting stdout.write i into the stmList var,
then proceed to insert the remaining stm commands.
The last step is to insert stmList into the
for_loop variable, and the for_loop variable
into the result.
It seems that I have a lot of space for explaining Juan’s macro. I promise that I will come back here, when I have time and answer all questions you have about tinkering with the Abstract Syntactic Tree. For the time being, you will need to be content with the examples, which Juan Carlos left here and there.
An improved rpn calculator¶
Now, let us revisit the problem of writing an rpn calculator. The previous calculator had a serious problem, it quitted the program between one calculation and the next, and the values stored on the stack were consequently lost. This problem was solved in the version shown in listing @calc. The calculators of listing @rpn and @calc are quite similar, and I believe that you will be able to figure out what is going on in listing @calc without further explanations.
The novelty in listing @calc is the stdin.readLine(s)
function that tries to read a line into s from stdin
and produces a Boolean true in case of success.
Then, the s var is tokenized and each token x is
presented to eval(x, stk) to be evaluated, as before.
Future value¶
Suppose that you wanted to buy a $ 100,000 red Ferrari, and the forecourt salesperson gives you the following two payment options:
- $ 100,000 now or
- $ 115,000 at the end of three years.
What to do when facing an increase in price to cover postponement of payment? The best policy is to ask your banker how much interest she is willing to pay you over your granted grace period.
Since the economy performance is far from spectacular, your banker offers you an interest rate of 2.5%, compound annually. She explains that compound interest arises when interest is paid on both the principal and also on any interest from past years.
The value of money changes with time. Therefore, the longer you keep control of your money, the higher its value becomes, as it can earn interest. Time Value of Money, or TVM for short, is a concept that conveys the idea that money available now is worth more than the same amount in the future.
import os, strutils, math
type LL= ref object of RootObj
car: float
cdr: LL
template car(a:untyped) : untyped=
if a == nil: quit("Empty stack")
else: a.car
template `>>` (a,b:untyped): untyped= LL(car: a, cdr: b)
proc eval(x: string, s: var LL)=
try: s= x.strip.parseFloat >> s
except:
case x:
of "+": s= (car s) + (car s.cdr) >> s.cdr.cdr
of "x": s= (car s) * (car s.cdr) >> s.cdr.cdr
of "/": s= (car s.cdr) / (car s) >> s.cdr.cdr
of "-": s= (car s.cdr) - (car s) >> s.cdr.cdr
of "expt": s= pow(s.cdr.car, s.car) >> s.cdr.cdr
of "fv": s= pow(1.0 + s.cdr.car/100, s.car) *
s.cdr.cdr.car >> s.cdr.cdr.cdr
of "neg": s= -(car s) >> s.cdr
else: quit("Error in eval")
var s= ""
var stk: LL= nil
var stack: LL= nil
stdout.write "> "
while stdin.readline(s) and s != "quit":
for x in s.splitWhitespace:
eval(x, stk)
stack= stk
while stack != nil:
echo stack.car
stack= stack.cdr
stdout.write "> "
(@calc) An improved calculator
Expression for calculating the future value¶
If you have $ 100,000.00 in a savings account now, that amount is called present value, since it is what your investment would give you, if you were to spend it today.
Future value of an investment is the amount you have today plus the interest that your investment will bring at the end of a specified period. Here is the relationship between the present value and the future value: \begin{equation} FV= PV\times (1+i/100)^n \label{eq:future-value} \end{equation} where $FV$ is the future value, $PV$ is the present value, $i$ is the interest rate, and $n$ is the number of periods.
In the case of postponing the payment of a $ 100,000.00 car for 3 years, at an interest rate of 0.025, the future value of the money would be 107,689.06; therefore, I stongly recomend against postponing the payment in this case. Let us use the calculator of listing @calc to check these amounts:
~/nim/tutorial/src
› make APP=rdwrt
nim c -o:rdwrt.x -d:danger --hints:off --nimcache:lixo rdwrt.nim
~/nim/tutorial/src
› ./rdwrt.x
> 2.5 100 /
0.025
> 1 +
1.025
> 3 expt
1.076890625
> 100_000.00 x
107689.0625
The Texan strikes again¶
Our Texan decides he needs a break. Thus he walks into a New York City bank and asks for the loan officer. He tells a story of how through his doctor’s recommendation he was taking it easy at his property in the south of France for two whole years and for such a medical emergency he needs a $ 10,000.00 loan.
The loan officer said that the interest was a compound 8% a year, but the bank would need some collateral for the loan.
“Well, I have a 60 year old car that I like very much. Of course, I cannot take it with me to France. Would you accept it as collateral?”
Unsure whether or not the old car was worth the amount of the loan, the officer summons the bank manager. The manager inspects the vehicle that was parked on the street in front of the bank. After a close examination, he gives a nod of approval: “It’s a Tucker Torpedo. Give him the loan.” Two years later the Texan returned, and asked how much he owed the bank. The loan officer started the rpn calculator, and calculated the total debt as $ 11,664.00.
~/nim/tutorial/src
› ./rdwrt.x
> 1.0 0.08 + 2 expt 10000 x
11664.0
> quit
After receiving the full amount due, the loan officer said: “We appreciated doing business with you, but I am a little perplexed. I checked that a Tucker Torpedo in mint conditions is worth more than 10 million dollars. Therefore, you must be a very rich man. Why you would bother to borrow $10,000?” The Texan replied: “Where else in New York City could I park my car for a whole two years for just a litle over one grand?”
Future value calculations are so important that I have included it in the rpn calculator of listing @calc, as you can check.
~/nim/tutorial/src
› ./rdwrt.x
> 10_000.00 8 2 fv
11664.0
Anthropology of Money¶
In order to build a computer that performs medical diagnosis, launch the Luna 3 to photograph the far side of the Moon, or even to apply to medical residency programs in 110 hospitals, you need three things: Money, training and collaboration. If I had not obtained the collaboration of Vindaar and Juan Carlos Paco, I would not be able to write about Nim macros. If the members of the Della-Vos group were not trained in such fields as biotechnologies, microelectronics and medicine, they would not be able to build bioFETs or measure ion-drifts in the ionosphere. Later, I will elaborate on training and collaboration. For the time being, let us learn the basics of money.
Money is a tool that provides three functions or services: Medium of exchange, store of value and unit of account.
To understand medium of exchange, let us perform a thought experiment. What would the economy in a Brazilian indian tribe look like, if that tribe lived without any significant contact with modern global civilization? Let us give this tribe a name– Awa, since I lived among the Awaians for almost three years and could observe their customs, and became friend of many members of the tribe.
There are people among the Awaians that I will call croppers, because they work in agriculture: they plant manioc, corn, rice and beans. There are also breeders that raise poultry for the eggs. The artisans produce artifacts like bows, arrows, wicker baskets, hammocks, etc. A potter provides ceramic ware, and also cups carved from wood. The healer knows the secrets of manufacturing medicines and alkaloid arrow poisons. There are also the hunter-gatherers that obtain foods and other goods by foraging, i.e., collecting plants in the forest and pursuing wild animals.
A hunter-gatherer girl, my friend Jurema, uses a blowdart for capturing small animals and defending herself. Curare is a common name for various arrow poisons that causes muscle weakness by competitively inhibiting one of the acetylcholine receptors. Let us assume that Jurema needs this concoction for her blowdarts that she uses for defending herself against the illegal gold panners that often invade the Awaian territory in the eastern Amazon rainforest. She goes to the healer and barters a parrot chick that she captured in the woods for a small quantity of curare. If the healer needs a ceramic cauldron for preparing chemicals and herbs, he may go to the potter’s tent and trade a quinine based malaria medication in exchange for the ceramics. A cropper can provide corn to the artisan and barters it for a hammock that she needs at home.
The aforementioned social organization is what anthropologists call a barter economy. The idea behind such an economy is that goods or services are exchanged directly and immediately, without delay. Of course, long term barter societies do not exist, and never did, although they can appear for short periods in countries plagued with rampant inflation.
To understand why a barter society would face serious economic crisis, let us suppose that the healer arrives with the quinine at the potter’s tent, but the potter already has all the quinine he needs for the time being:
“I am sorry my friend, but I still have the whole lot of quinine that you provided me the last time we bartered. Since Madam Tu Youyou discovered artemisin and Chinese merchants are providing us with the drug, quinine is not much in demand anymore.”
In this case, he would not provide the cauldron that the healer needs so badly. It is also possible that Jurema will not be able to get the curare in exchange for the parrot chick: The healer may not like parrot chicks, or his daughter may already have five parrot chicks, and he does not want to humor her and add a sixth chicken to her collection.
The problem with a barter economy is that the buyer pays with a very specific item that the seller may not need or cannot store at that particular moment. A small improvement to the barter economy that could make it viable would be a gift exchange system, where the buyer pays with a debt of gratitude. In such a social organization, Jurema goes to the healer and obtains the needed curare without any immediate exchange of goods. This therefore means that she now owes a favor to the healer, which is better known as a debt of gratitude. How does one pay a debt of gratitude? In this case, in the future, when the healer needs feathers for ceremonial dress in a ritual, he can order Jurema to collect feathers of color and type he needs during her next forage in the forest. On the other hand, the healer would receive the cauldron from the potter without immediate payment. When the potter needs a mosquito repellent from the healer, all he needs to do in order to obtain it is to remind the healer of the cauldron received as a gift.
The Awa tribe actually exists as a gift culture. This is only possible due to the fact that the Awaian population consists of few individuals. Awaians can remember the persons to whom they owe favors, and who owes favors to them. If a society becomes large, it is difficult for a seller to track the many people who have debts of gratitude to pay. It is also difficult to decide what could be consider as equal payment between debts of gratitude. How many times does the healer need to provide medicine for a cauldron? Is a repellent for mosquitoes equivalent to a bottle of quinine? How many feathers are necessary to pay for a portion of curare?
Therefore, large human populations created tokens to remind people of their debts of gratitude. For instance, Mayans used cocoa beans as debt reminders. The advantage of such a system is that a Mayan did not have to receive the debt only from the person to whom he provided a service. In such an organization, a Mayan healer could take the cocoa beans that he received from the hunter-gatherer girl and use them to pay the potter for the cauldron.
Cocoa beans as a medium of exchange also have a problem: It is very easy to cheat the system. For instance, a Mayan crook could find a cocoa tree, harvest a lot of cocoa beans, and tell the potter, the healer or the hunter-gather girl that they owe him that many favors. To avoid this kind of dishonest behavior, most civilization replaced simple tokens such as cocoa beans with something harder to falsify, such as coins of gold, silver and other rare metals.
Of course, falsifications continued even after the introduction of metal coins. People minted coins of tin, and gold plated them. Therefore, the gypsies used to bite the gold coins to check that they had the consistency of gold. Another trick to cheat the system was to scrape some gold from the edge of a coin. To prevent this, minters added ridges to the edges. Now you know why coins have ridged edges.
Coin is the name that experts give to metallic tokens for debts of gratitude. Gold and silver provides a good method of preventing people from counterfeiting coins. However, governments decided to replace gold with a less expensive token. The substitution has the added advantage of liberating gold reserves for other uses, such as manufacturing gold nano particles for biomedical diagnostic assays. In fact, gold is very good for building a device called lateral flow assay, since it has low toxicity. Besides this, there exist simple synthesis methods for producing Gold Nano Particles quickly and inexpensively. If you don’t find a discussion of the subject in this book, get in touch with the authors and ask for a chapter on the subject.
For the reasons stated above, gold and silver coins were replaced by banknotes. In order to defeatforgery, tampering and counterfeiting, manufacturers of banknotes introduced many technological security measures, such as special types of paper, micro printing, intaglio printing, watermarks, guilloché, holograms, security threads, magnetic ink, etc. One of the most famous security printers, who helped in the creation of these technologies, was Thomas de la Rue (1793 – 1866), who founded the De La Rue plc, which today sells high-security paper and printing technology for over 150 national currencies.
The function of banknotes, which a citizen holds in his or her possession, is to remind the society that its members owe a certain value of services and goods to that particular citizen. It was introduced when the number of citizens became so large that a person, like the Awaian girl, could not remember who should pay her a debt of gratitude. The advent of computers permitted the storing of commercial transaction records in a data base. The buyer and seller can access the data base through a smart card personalized to the buyer. This new technology is known as digital currency.
It is easy to forecast the type of technology that the future holds for money: The seller and the banking system will not need the smart card, in order to identify the buyer, since they can easily be identified through their DNA.
A syntax changing macro¶
# A syntax changing macro by Vindaar
import macros, strutils, os
proc parseArgs(cmd: NimNode): (NimNode, NimNode) =
doAssert cmd.len == 2
expectKind(cmd[1], nnkInfix)
expectKind(cmd[1][0], nnkIdent)
expectKind(cmd[1][1], nnkIdent)
expectKind(cmd[1][2], nnkIdent)
doAssert cmd[1][0].strVal == "->"
doAssert cmd[1][1].strVal == "times"
result = (cmd[0], # cmd[0] must be valid integer
cmd[1][2]) # identifier to use for loop
macro rpt(cmd: untyped, stmts: untyped): untyped =
expectKind(cmd, nnkCommand)
expectKind(stmts, nnkStmtList)
let (toIdx, iterVar) = parseArgs(cmd)
result = quote do:
for `iterVar` in 1..`toIdx`:
`stmts`
echo result.repr
rpt paramStr(1).parseInt times -> j:
echo j, "- Give me some bear"
echo "Now"
(@sugarmacro) A syntactic sugar macro
In listing @sugarmacro, the untyped stmts behave
exactly as in the other macros used for repetition
that I discussed previously. However, cmd is a NimNode
that bundles the integer expression that determines the
number of repetitions, the keyword times, the infix
arrow -> and the j counting variable. These roles
are determined by the parseArgs procedure that extracts
the important components of this complex syntax, to wit,
the integer toIdx parameter that indicates the number
of repetition and the iterVar that in the example is j.
The parseArgs procedure is amazing, and I would not
be able to design it the way Vindaar did. It starts with
a doAssert cmd.len == 2 that determines that cmd has
length 2. Of course, cmd[0] contains the integer number
of repetitions. As for cmd[1], it contains three components,
the arrow (component cmd[1][0]), the keyword times (component
cmd[1][1]) and the iterVar, which is j in the example.
Of course, the result will be the (cmd[0], cmd[1][2]) tuple.
With the four examples of macros that you and I discussed,
you will be able to become proficient in meta programming
through deliberate practice.
The tacit dimension¶
There are two persons that are helping me with this book, I will call them edu500ac and Marcus. I do not know much about Marcus, except that he has three daughters, and that his daugters play the violin. Mr. edu500ac told me that much about Dr. Marcus, therefore that much is all I know about him.
Brian Caplan says that, if a girl wants to play the violin at Carnegie Hall, she needs to practice a lot. I think that you do not dispute this assertion.
Airline transport pilots must have a minimum 1,500 hours of flight time. From this training, at least 500 hours should be cross-country flight time and 100 hours should be night flight. I don’t know why I am trying to make this point, since everybody accepts that a pilot must practice a lot before flying a passenger jet. It is interesting that people who accept that musicians, physicians and pilots need training do not take this idea to their own activities.
\begin{figure} \begin{tikzpicture} %aixes knowledge \draw[thick,->] (0,0,0) – (3,0,0) node[anchor= north west]{$y$}; \draw[thick,->] (0,0,0) – (0,2,0) node[anchor= north west]{$z$}; \draw[thick,->] (0,0,0) – (0,0,5) node[anchor= south east]{$x$};
%dashed \drawdashed – (2.5,0,4); \drawdashed – (2.5,0,4); \drawdashed – (2.5,2,4); %% \drawdashed – (1,1,1);
\drawfill=black!100!white circle(.08); \end{tikzpicture} \caption{Position} \label{fig:position} \end{figure}
In this chapter, you will learn that knowledge has 3 dimensions, the explicit knowledge, the tacit knowledge and the shared knowledge. You can acquire explicit knowledge from books and classes, but you need practice in order to gain tacit knowledge. For instance, you learned the structure of Nim macros, but without writing a lot of macros you will never become as proficient as Vindaar.
How to recognize an object? How to distinguish a screwdriver from a monkey wrench? A set of attributes that characterize an object is called data. Examples of attributes that could be used in a classification system: color, position, mass, volume, density, material, etc. Each attribute can have different values. For instance, the color attribute can be black, white, yellow, blue, and so on. The position on Earth is an attribute that is usually given by latitude and longitude. Mass can be measured in kilograms, grams, pounds, etc. Volume may be given in liters.
\begin{figure} \begin{tikzpicture} %aixes knowledge \draw[thick,->] (0,0,0) – (3,0,0) node[anchor= north west]{$y$}; \draw[thick,->] (0,0,0) – (0,2,0) node[anchor= north west]{$z$}; \draw[thick,->] (0,0,0) – (0,0,5) node[anchor= south east]{$x$};
%dashed \drawdashed – (2.5,0,4); \drawdashed – (2.5,0,4); \drawdashed – (2.5,2,4); %% \drawdashed – (1,1,1);
\drawfill=black!100!white circle(.08); \end{tikzpicture} \caption{Position} \label{fig:position} \end{figure}
According to Descartes, there exists multidimentional
attributes. In modern terminology, one says that the
values of such an attribute are vectors that can be
broken into parts, those partes are called components.
For instance, the position attribute has three dimensions,
which are the x, y and z coordinates. Likewise, one
can see knowledge as having three dimensions, which are
the explicit, tacit and shared components.
Explicit knowledge is anything that one can write in a book, code into a computer program or teach in a class room. Tacit knowledge is something that one knows, but cannot explain how she learned it or use it. Mexicans know Spanish, but they aren’t able to write a primer where a resident physician from Miami could learn to speak fluently to his patients. The difficulty in teaching Spanish to an adult shows that Michael Polanyi was right when he stated that we can know more than we can say.
\begin{tikzpicture} \draw[thick,->] (0,0,0) – (2.2,0,0) node[anchor= north west]{$tacit$}; \draw[thick,->] (0,0,0) – (0,2,0) node[anchor= north west]{$shared$}; \draw[thick,->] (0,0,0) – (0,0,3) node[anchor= south east]{$explicit$};
\drawultra thick,-> – (0,0,2); \drawultra thick,-> – (2.5,0,2); \drawultra thick,-> – (2.5, 2,2); \draw[dashed,->](0, 0, 0) – (2.5, 2, 2); \end{tikzpicture}
(@kdimensions) Dimensions of knowledge
In figure @kdimensions, one can see a path to knowledge. About 1418, Prince Henry the Navigator founded a School of Navigation in Sagres. In class rooms, a future sailor was trained in map-making and reading, which is explicit knowledge that one can write in books. The student would advance along the explicit axis, as shown in the figure. Then he would embark in a ship, where he would acquire actual job skills through hands-on training. Could a sailor learn about maps while already in a ship? Such a training method is represented by the dotted path in figure @kdimensions and is very dangerous. It is like a physician who would consult the Sobotta to learn Anatomy while performing a surgery.
One acquire tacit knowledge through training, there is no other way. Don’t expect to learn how to play the violin, wrestling, deliver babies or pilot a jet plane in class room or from books and youtube videos.
The shared knowledge is the one that cannot be found between our two ears. It is distributed throughout organizations or guild of experts. For instance, the knowledge about air combat, on which Manfred von Richthofen – the Red Baron – excelled, was distributed between the pilot, who was the Baron himself, and Anthony Fokker, the Dutch engineer that designed the Manfred’s triplane. This knowledge was seamed so well that the Baron could not perceive the stitches. The Red Baron feel any gaps in his domain of the airplane, even if the gaps were filled by automatic contrivances hard wired in the controls by Anthony Fokker. In fact, any perceptible transition between engineering expertise and flight tacit knowledge could hinder the pilot’s ability to anticipate the consequences of his actions and be fatal in a battle.
I am telling you all this in a tentative of convince you that this book alone will not take you very far from the axis of explicit knowledge.
Now, I will give you time for practicing macros. Meanwhile, I will tell you my story, and how I got here in Paraguay. Of course, if you are not interested in my story, you can stop reading here, and start practicing macros, while your teen ager daughter train how to play the violin.
Variations on a theme of Vindaar¶
# counter.nim
import macros, strutils, os
proc parseArgs(cmd: NimNode): (NimNode, NimNode) =
doAssert cmd.len == 2
expectKind(cmd[0], nnkIdent)
result = (cmd[0], # cmd[0] has an integer expr
cmd[1]) # identifier to use for loop
macro cnt(cmd: untyped, stmts: untyped): untyped =
expectKind(cmd, nnkCommand)
expectKind(stmts, nnkStmtList)
let (iterVar, toIdx) = parseArgs(cmd)
result = quote do:
for `iterVar` in 1..`toIdx`:
`stmts`
echo result.repr
cnt j paramStr(1).parseInt:
echo j, "- Give me some bear"
#[ › make APP=counter
nim c -o:counter.x -d:danger --hints:off --nimcache:lixo counter.nim
for j in 1 .. paramStr(1).parseInt:
echo j, "- Give me some bear"
› ./counter.x 2
1- Give me some bear
2- Give me some bear
]#
(@practice1) A simpler counting macro
When Vindaar provided us with the macro on
listing @sugarmacro, he gave us explicit
knowledge. In fact, since he could present the
macro on paper, it was explicit knowledge. In
order to learn macro designing, it is necessary
practice, and one should start practicing with
simple stuff. In listing @practice1, the definition
of cnt couldn’t be simpler. The cmd parameter
has 2 elements, the first one must be a variable.
The statements below checks whether these two
conditions are met by the cnt macro.
doAssert cmd.len == 2
expectKind(cmd[0], nnkIdent)
More Variations¶
# infixLoop.nim
import macros, strutils, os
proc parseArgs(cmd: NimNode): (NimNode, NimNode) =
expectKind(cmd[0], nnkIdent)
expectKind(cmd[1], nnkIdent)
doAssert cmd[0].strVal == "++="
result = (cmd[1], cmd[2])
macro rpt(cmd: untyped, stmts: untyped): untyped =
expectKind(cmd, nnkInfix)
expectKind(stmts, nnkStmtList)
let (iterVar, toIdx) = parseArgs(cmd)
result = quote do:
for `iterVar` in 1..`toIdx`:
`stmts`
rpt j ++= paramStr(1).parseInt:
echo j, "- Give me some bear"
#[
› nim c -o:infixLoop.x -d:danger --hints:off infixLoop.nim
› ./infixLoop.x 3
1- Give me some bear
2- Give me some bear
3- Give me some bear
]#
(@practice2) Macro with an infix operator
Listing @practice2 is my second attempt at building
an interesting macro. This time, cmd has a single
infix expression. I learned that I should not place
an assertion on the length of infix expressions.
For instance, the compiler protests if I add the
following check on the definition of parseArgs in
listing @practice2:
proc parseArgs(cmd: NimNode): (NimNode, NimNode) =
doAssert cmd.len == 2
expectKind(cmd[0], nnkIdent)
expectKind(cmd[1], nnkIdent)
doAssert cmd[0].strVal == "++="
result = (cmd[1], cmd[2])
It seems that infix expressions do not have length. I would never discover this if I have not been practicing in the last three days.
Nightmares¶
I was born in Provo, a small town in Utah, about 82 miles from Salt Lake City. If you are not acquainted with customary units, you will find a good opportunity to practice Nim in the American units of measurement. Therefore, let us interrupt my story and deal with unit conversions. Let us consider only conversions between miles and kilometers for the time being. You will discover easily how to deal with other units. Below, you can see how to use the program of listing @units.
~/nim/tutorial/src
› make APP=units
nim c -o:units.x -d:danger --hints:off --nimcache:lixo units.nim
~/nim/tutorial/src
› ./units.x
> 82 mi km
131.938km
> q
As you are probably aware, there are a lot of Mormons in that region of the United States. I myself am an atheist, as befits a physician. The rest of my family are members of The Church of Jesus Christ of Latter-day Saints, which is the official name of the Mormon Church. Since The Church of Jesus Christ of Latter-day Saints is a very long name to write or pronounce, Mormons often abbreviate it as The LDS Church, an acronym that reminds me of a popular hallucinogenic drug.
A Mormon believes in many weird doctrines. According to the doctrine of continuing revelation, Jesus Christ leads the LDS Church by revealing his will to its president. The belief is also that each individual member of the church can receive personal revelation from God, while getting on with conducting his or her personal life. However, I never did, which makes me the only Mormon to whom God never revealed anything!
Who is this guy that calls himself God? Apparently, he is a king that rules the Earth from his throne somewhere near the star Kolob.
# make APP=units
import os, strutils
type
LL= ref object of RootObj
h: U
t: LL
UnitKind= enum mi= "mi", km= "km", nm= "nm"
U = ref object
case kind: UnitKind
of mi, km, nm: fVal: float
template car(a:untyped) : untyped=
if a == nil: quit("Empty stack") else: a.h
template psh(knd: untyped, v: untyped, s: untyped) =
s = LL(h: U(kind: knd, fVal: v), t: s.t)
proc eval(x: string, s: var LL)=
try: s= LL(h: U(kind: nm, fVal: x.strip.parseFloat), t: s)
except:
case x :
of "km":
if (car s).kind == nm: (car s).kind= km
elif (car s).kind == mi: psh(km, s.h.fVal * 1.609, s)
of "mi":
if (car s).kind == nm: (car s).kind= mi
elif (car s).kind == km: psh(mi, s.h.fVal / 1.609, s)
else: echo "?"
var s= ""
var stk: LL= nil
var stack: LL= nil
stdout.write "> "
while stdin.readline(s) and s != "q":
for x in s.splitWhitespace: eval(x, stk)
stack= stk
while stack != nil:
echo stack.h.fVal, stack.h.kind
stack= stack.t
stdout.write "> "
(@units) Unit conversion
I am not entirely sure whether the existence of Kolob is truly an official doctrine of the LDS Church. In fact, I never cared to ask for an audience with the Mormon Church President, in order to learn the whereabouts of God. But my grandmother was said to have received a revelation that firmly placed God’s home in the neighborhood of Kolob.
A Mormon male who abides by the convenants that he himself or by proxy made with God may be considered for priesthood as early as the age of 12. Let me give you my impressions concerning this particular doctrine. I think that religion should have a content rating system similar to the Motion Picture film rating system. Buddhism and Jainism could be classified as entertainment for general audiences. The Seventh-day Adventist Church do have some material that may not be suitable for children. Therefore, a child, who wants to attend the Seventh-day Adventist Church, should receive guidance from a biology teacher or a philosopher. Teenagers under 17 must be accompanied by an adult guardian, in order to attend any other Christian Church. Finally, no one, 17 and under, should be admitted in a mosque or synagogue.
There are people, such as the biologist Richard Dawkins, who think taking a kid to a Christian temple is tantamount to child abuse. Perhaps due to a degree of ignorance about Dawkins’ books, my grandmother started to take me to church, while I was still indeed very young. I cannot remember how old I was when I entered a temple for the first time, but I can assure you that I was under 17. Notwithstanding, I don’t want to discuss this child abuse issue any longer.
Another strange doctrine preached by the LDS Church is the so called law of chastity, which prohibits adultery, all homosexual behavior, and any sexual relations outside of marriage. The impact that this law had on my life was that I only started a normal sex life at almost 30 years old; it was then that I discovered all doctrines of the LDS Church to be bullshit.
To be fair, I must accept that Mormons are very tolerant, as the following story will bear witness. A Study in Scarlet is novel by Arthur Conan Doyle, where this Scottish author introduced Sherlock Holmes and Dr. Watson to the world. Arthur Conan Doyle imitates the style of the French detective novels by Émile Gaboriau, who always starts his stories with an investigation and presents a long flash back at the second part of the book.
Doyle’s story flashes back to a valley in Utah, where nowadays is Salt Lake City. If you read the book, you know that it paints a bleak portrait of Mormonism that includes forced marriage and violence. I was browsing the novel in a large bookstore in Logan, Utah, when many members of the LDS church approached and recommended the book. They have no hard feelings against the Arthur Conan Doyle, and I am sure that I will not lose a single Mormon friend for my bland humor directed against the Church.
There is a custom among members of the LDS Church that is worth preserving. Young Mormons often go to distant countries as missionaries. This means that many couples teach foreign languages to their kids, when they are quite young, so that they are apt to spread God’s word to non-English speakers. For instance, my parents wanted me to serve as a missionary among South American Indians. To fulfill my father’s design for me, I started learning Portuguese and Spanish when I was 3 years old. Of course, we did not know at the time that Indians, as a rule, do not speak either Portuguese or Spanish.
To my regret, my father never saw me taking an airplane from Salt Lake City airport, in order to teach the Book of Mormon to Brazilian, Peruvian, Bolivian or Paraguayan Indians. Instead of giving this simple joy to my father, I decided to go to college when I was 16 years old, and started medical school when I was 20. After medical school at the Johns Hopkins School of Medicine, I spent an additional five years in a general surgery residency. Therefore, I was over thirty years old when I finally took an airplane to Brazil. My father did not go to the airport to say goodbye. He passed away three years before due to a colorectal cancer.
As I said before, my father was not at the airport for reasons of force majeure. But my grandmother was there. She entrusted me with two large boxes for the Indians, or Lamanites, as she used to call them. One of the boxes contained Portuguese translations of The Book of Mormon. The other box was heavy with Spanish versions of the same book. The sacred books were quite useful in South America, since my stock of toilet paper became soaked due to bilge water in the boat, which I used for traveling along the Amazon river. On the other hand, my grandmother’s boxes were so carefully packaged that no single book was touched by water. So the exemplars of the Book of Mormon provided a good replacement for my lost toilet paper.
Believe me, I will provide you with a full account of my years in college, the medical school at Johns Hopkins, and my residency training. However, right now I want to report on an event that happened while I was living among members of an Indian tribe in the north of Brazil. I will not name the tribe, due to the Hippocratic oath, that forbids me to divulge in any shape or form whatever I see or hear in the course of my profession. In any case, I already named it when I was writing a chapter on money. The fact is that, when I writing about women, money or Italian poetry, I don’t consider myself a physician, and am not bound to ancient oaths and convenants.
Upon arriving in Brazil, I heard of a government program by the name of Mais Medicos, which issues a temporary medical license, on the condition that the applying physician takes a job in a remote region of the country. The pay amounts to 3000 US dollars a month. In this list of remote regions, there are a few Indian tribal territories.
By the way, the word Indian is the accepted term that Brazilians use, when they refer to people descended from the Pre-Columbian indigenous population of the land. Instead of calling these populations by some polite noun phrase like Native American, while depriving them of their lands and properties, Brazilians reserved 12.5% of the national territory for Indians. All the same, Brazilians still call them bluntly – Indians. If a tribe proves that its ancestors lived in a given region, it can incorporate that region to their current tribal land. This constitutional act applies to any tribe, no matter how large the region is, or how few individuals belong to the tribe. For instance, Fox/Sun Hills Indigenous Land is the home to 20000 members of the Macuxi people. Its perimeter is 629 miles long. In May 2009, the Brazilian Supreme Court ruled that the Fox/Sun Hills Indigenous Land should be inhabited only by indigenous people, and ordered a military operation to remove all non-indigenous inhabitants. With the addition of Fox/Sun Hills reservation, 46% of the State of Roraima is set aside for Indians.
Of course, Brazilian doctors don’t want their practices in a reservation. Therefore, Brazilians who live in large cities like Salvador or Rio de Janeiro form long lines in front of large hospitals staffed by physicians from prestigious local medical schools, like Unipac or Unifeso. The Indians must be content with a doctor graduated in places like Johns Hopkins School of Medicine, Harvard Medical School or Université de Médicine Paris Descartes.
I must confess that, when I applied for the job, my goal was not to help poor Indians who live somewhere in the north of Brazil. I was envisioning trips along large rivers on a jet ski with a pretty French female doctor riding the pillion.
I must avow that the reality departed from my daydreams in many aspects. The girl who often rode on the pillion was not French, but an American of Danish descent. If you know Logan, the home town of the Utah State University, my Alma Mater, you know that there are a lot of people of Danish heritage there. Family names like Jensen, Mikkelsen and Jorgensen are commonplace in Logan. Therefore, I was very disappointed when I discovered that the closest European girl from my practice was in fact not only Danish, but a Mormon Dane.
I am sure that you will ask: “Well, what is the difference if the girl is French or Danish?” As a French man would say, Il y a une différence (there is a qualitative difference).
You certainly noticed that American or English men go simply crazy over French, Iranian or Armenian women. But if a French or Armenian man shows interest in an American woman, he wants to marry her to obtain the right to stay in the United States. Sorry, guys, what I said is politically incorrect, but Truth is often politically incorrect.
A research team showed pictures of pretty women from different countries to 44000 men in the United States. The preference rating of American men was as follows. Armenian women came first. Bajan women came in second place in the preference of American men. Don’t ask me where Bajan women come from. I do not have the slightest idea. French women come third, followed by Colombian, Brazilian and Bulgarian women in that order. American and English women occupied the 9th and 10th place in men’s preference respectively. This result would be great for American women, if the number of contestants were not 10.
Why do men prefer certain nationalities? The answer is the ass. Germanic women often have square butts. By Germanic women, I mean Anglo-Saxon, German and Scandinavian women. A square or H shaped butt is due to the position of the hip bones, excess fat around the waist, love handles or genetics. Armenian, Colombian and French women have a bigger, rounder and shapely booty. Before proceeding with my narrative, I will answer the question that my American female readers are impatient to ask. “Doctor, is there a cure for a square shaped butt?”
Before answering the question, I will remind the reader, be it female or male, that Brazilian indigenous people don’t mind being called Indians, provided that they receive 12.5% of the national territory. I hope that American women will forgive me for being rude to the point of saying that most of them have square butts, provided that I tell them how to get an Armenian butt. And that is the main point of this book: A sure and safe way to loose weight and get a round and shapely ass.
As for my Danish girlfriend, after two years with me in the Amazon rain forest, and through following my advice, her butt became so pretty that you would take her for a Colombian Wayuu Indian, if she were not blond. Unfortunately, since she is a Mormon, the only kind of intimacy that I shared with my Danish girlfriend were jet ski trips.
Now, I will start my narrative at the point in time, when I was traveling on foot to the Indian reservation that the Mais Medicos program assigned to me. Pülowi, my guide, was a young Wayuu Indian girl that entered Brazil illegally across the Venezuelan border. Due to the economic crisis in Venezuela, many Wayuu Indians like Pülowi moved to Brazil, where they pretend to be native Macuxi.
I did not care to ask the name of the town that Pülowi and I were crossing on that occasion, because a village in the middle of the jungle like that one often doesn’t have an official name. It is also possible that different groups of people call it by a different name. A policeman that the authorities have sent to keep law and order may call it Hellgate! On the other hand, a drug dealer who takes a break there while traveling to Colombia or Peru prefers Stopover. Since I did not learn its name, I cannot point to that weird settlement on a map or give you any information about its location. What I can say is that the river that flows through the town flooded, a phenomenon that very often accompanies the rainy season in that part of Brazil. As long the rain lasts, a torrent of water flows along the street that runs parallel to the river, and at that time it was no different.
At last the rain ceased. The right hand sidewalk and the street itself was almost dried out. There was no car to be seen. I must add that there are not many cars in the small towns of the Amazonian rain forest. A boat is more useful in that region than a car. In that particular town that Pülowi and I were crossing, one could use their fingers to count the number of cars.
On the right hand sidewalk, instead of normal buildings and houses, I noted only white painted walls. The height of the walls was not uniform, but changed according to the plot of land that it was marking. Notwithstanding, every estate seemed to be surrounded by walls tall enough to hide from view the terrain and every building that one could imagine on it.
What secrets were being hidden from inquisitive eyes? Perhaps smuggled goods? Maybe, that street was a string of chemical laboratories manufacturing illegal drugs. Another reasonable hypothesis is that the plots of land were used to park containers of weapons or stolen goods. I know that, when you reach the end of this book without learning the purpose of these high walls around the tracts of land you will be extremely frustrated. But, believe it or not, I was too scared to stay any longer in that unwelcoming place. What follows will show you that my fear was not misplaced. Due to my unwillingness for any additional exploration, those walls brought only one contribution to this logbook: The inhabitants of the town that Pülowi and I were traversing are not good and law abiding people. It would not take long before my suspicion was confirmed.
Before proceeding with the narrative, I will ask the reader to ponder for a moment about the layout and surprising aspect of the scenery in the street, through which I and Pülowi were walking. A river flows on the left hand side. On the right, there is a line of walls without gates or entryways. How can the owners or their employees reach the buildings or tracts of land that the walls surround? In my mind, I was asking these questions, and to which I never found a satisfying answer.
Only a far away building broke the disparate line of uneven walls. In front of the building, that perhaps was a movie theater, there was a compact mass of people.
The building still was far away, nonetheless I started planning how to make my way through the mass of people to carry on my journey.
I walked slowly due to the heat that danced in the still air. One hundred meters in front of me, Pülowi was running. She was close enough for me to see with pleasure the swinging movement of her buttocks. Whenever she thought that she had distanced far enough away from me, Pülowi would reverse the step, run in my direction, and stop 50 meters in front of me. There she would practice the monkey jump, the half moon, and other moves very popular among Brazilian martial arts practitioners. After this display, she would run again forward along the chosen path.
This way, I was walking with regular steps, while Pülowi kept running forward and backward, in a zigzag movement. Of course, she would displace herself in ever longer distances going forward than coming backward, so she could advance at the same speed as her companion, of course that was me.
Since that town seemed to be so dangerous, people may wonder why I kept such a slow pace. The northern part of Brazil is hot as hell, that is why! During the day, the temperature often reaches 100 Fahrenheit. What I think is amazing is not my lumbering, but the zigzag jogging of the Indian girl.
Although we were advancing very slowly, due the slow pace that the heat imposed on me, and Pülowi’s zigzag jogging, we finally reached the throng of men in front of the movie theater. The methods that each one of us chose to cross the horde could be used by a psychologist to draw our profile.
The Indian girl penetrated the crowd boldly, poking people who were at her right and left sides, kicking anyone in front of her, squeezing herself forward like a determined winding snake, while stepping on any foot that was in her way. Don’t ask me how she was able to avoid harassments from the bullies and attacks from the thugs that were gathered in their element. It is possible that the ruffians thought that she was the lover of a local drug lord. After all, what kind of woman could dare to jump in the middle of such a dangerous crowd, unless she felt herself protected by a top dog?
As I told you, there is a river that flows along the left hand side of the street. The overflowing water spread over the left hand sidewalk. A long flatboat was moored across the throng. The layout was such that the crowd took up completely the narrow space between the river ship and the movie theater leaving no room for easy passing. In fact, the river ship was in itself long enough in that the bow and stern were free of this multitude. I figured that if I entered the vessel at the bow, walked along its deck, and disembarked at the stern, I would get around the crowd. The point for me was the boat, in that position, stood out like an invitation around trouble. I guess that an FBI profiler who might observe me performing this maneuver, would deem me a coward, a man prone at all cost to avoid confrontation. Pülowi, to the contrary, would be classified by the same profiler as a risk taker.
The ship’s taffrail formed the outermost wall of the cabin. Judging from the size of the cabin, one could infer that the boat was a floating home. However, the owner was elsewhere in all likelihood. He could even be mingled in with the crowd in front of the movie theater, trying to do whatever the others were doing. The cabin door opened on deck side, towards the river. Then I could not see the man who was crouched at the entrance, and the circumstances seemed to indicate that nobody was home. Therefore, when I jumped on the deck, and started towards the stern, I was startled by a voice coming from my right hand side shouting – “What are you doing on my boat?”
My error is understandable. At the time of these events, I did not know that people do not leave their houses unattended in Brazil. If somebody is stupid enough to leave his house without a guardian, theft is certain, and invasion followed by squatting is very likely. I cannot resist the temptation of comparing Brazilians with Russians in this particular. When I studied at the Bauman University, in Russia, I knew Victor Bojarczuk, a mathematician whose parents and brothers lived somewhere in Siberia.
When the Bojarczuk family traveled to a far away town, in order to buy supplies and tools, Mother Bojarczuk would prepare non perishable food and fuel for heating. Therefore, if a traveler should get lost in those vast frozen expanses, he would find a welcoming abode, a refuge, which would protect him from the cold, through providing firewood, food and water. Mother Bojarczuk did not hope for gratitude from the men and women that she helped along her life. It is a fact that many men, women and even children enjoyed the anonymous hospitality of the Bojarczuk family and other Russians that share these beautiful traditions and practices. But Mother Bojarczuk never met any of these persons that she saved from a horrible and almost certain death. On the other hand, Victor told me that his family never missed anything of value that they left in the house. Travelers would eat the food, use the firewood, sleep in the beds, but would not steal a thing. Since I don’t want to leave this behavior without witness and mention, I will list here the names of some people who are members of the Bojarczuk family: Leon, Victor, Nina and Tom.
The deck of the flat bottomed boat sat only 2 feet above the water level. Therefore, the design of the ship made it easy for me to throw my medical bag over the rail, and raise myself onto the bow deck. There, I quickly recovered my medical bag, and started to walk friskily towards the stern. As I said before, the ship master’s voice stopped me abruptly in my tracks: “What are you doing on my boat?”.
The man, to my reckoning, was about fifty years old. However, it is hard to know the exact age of people who live in that region of Brazil by appearances, as their skin is marked by wrinkles and grooves. These deep skin furrows can be explained both through old age, or constant exposure to the hot tropical sun, which also accentuates skin grooves.
If natives from northern Brazil were there with me in front of the boat dweller, they would not be able to say for sure whether that man had ancestors among South American Indians, Africans or Europeans, but his forefathers certainly came from one of these parts of the world. In Brazil, the climate and the methods used to earn a living have deeper influence on the phenotypical aspect than does ethnic origin.
The boat dweller had a length of tobacco, which looked like a thick piece of rope. This he was chopping very finely with a curved knife. The making of straw cigarettes from rope tobacco is very popular among Brazilian men who live in the country side. The behavior of chopping tobacco is relaxing, and this psychological addiction adds to the effect of the nicotine. In fact, many Brazilians claim that they managed to get rid of the habit of smoking, but they could not stop tobacco chopping and hand rolling straw cigarettes. An important component of the behavior is to perform tobacco chopping while crouching on one’s heels. Researchers observed that chopping tobacco and hand rolling straw cigarettes consume so much time that country side Brazilians end up smoking moderately. At least, if one has to chop tobacco and hand roll one’s own cigarettes, chain smoking becomes impossible.
When I mentioned the curved knife that the Brazilian boat dweller was using to chop tobacco, the reader certainly imagined some kind of weapon similar to the Turkish scimitar. However, the tobacco chopper’s knife did not have the cutting edge on the outer part of the blade curvature. The edge of the Brazilian knife is in fact found within the curved blade. A good way to imagine this knife is as a cutting hook. The ship master did not wait for me to arrive at any conclusion as to the goal of such a knife design.
“What are you doing on my boat? I will answer this question myself. You thought that I am an old man, therefore you can enter my house, steal my property and kill me in the process, if necessary. After that, you would probably rape my granddaughter. But I have something to tell you. I may be stronger than you, or perhaps you are stronger than me. In any case, do you see this hooked knife? Do you know why it has a cutting edge curved to the inside? I will answer you this question as well, for you do not seem to know local customs. In my land, that you are visiting, one uses this kind of knife to castrate pigs. The curvature hooks around the testicles, and all one needs do is pull on the knife, in order to complete the task. Since you are a curious man, you certainly have another question. Why do I need such a long knife for castrating piglets? The fact is that this knife has two functions. The first one is to castrate pigs, as I already made clear. The other one is to gut intruders. I am a civilized fellow, and do not usually castrate men before gutting them. However, I may make an exception in your case, since you certainly intended to rape my granddaughter. In this special circumstance, castrate before killing is not an unusual or cruel punishment.”
I tried to show myself as being calm and collect in light of the circumstances I now found myself in, while replying to the long diatribe of the boatman. “You are mistaken, my friend. I am not a thief, murderer or rapist. All I want to do is to go around that mob over there. That is the only reason for my entering your flat bottomed ship.”
At this moment a girl came out of the cabin. She was the granddaughter of the old man, to be sure. She was wearing a sooted dress, which was white at some point in time. However, the girl often held and shook it over an open flame in order to kill fleas and ticks. The girl’s hair was tangled and dirty. She was holding a rag doll, which had lost the two arms and one leg. The doll’s skirt was also gray with soot, just like the girl’s dress. I guess that the girl held and shook the doll over the fire, in order to kill imaginary ticks. Another possibility is that she used her old clothes to make skirts and dresses for the doll.
Suddenly, the girl spoke. “Grandfather, after killing this bad man, and before throwing the body into the river, cut his hair off for me. I need it for Rachel’s wig. The hair of the other bad man, which I sewed to my doll’s head has almost entirely gone.”
The old man answered the girl: “I am not sure whether this man is really evil. After all, he has not hurt you or me. Of course, I don’t know what he would do, given the chance. For the time being, he is only a trespasser. Anyway, my dear, I still have not had the time to interrogate this individual, as to whether he did not attack us for lack of opportunity or for not being of violent intent. In the latter case, I will give him a speedy death by cutting his throat, and throwing his body over the rail. Besides this, if he is only a trespasser or a mere thief, I don’t intend to mutilate his face or defile his body. But if he is a rapist or a murderer of children, then I need to make him an example for others with like character. A rapist deserves to be gutted and lay in agony on the deck before being thrown into the river. Whatever is my decision, I think you should enter the cabin. You are too young to witness an execution.”
At this moment, I felt the need to interrupt this not so delicate conversation between this loving grandfather and his lovely granddaughter. This was not due to my having any preference concerning the methods proposed for my death, but purely to gain some time. “I ask you, dear Sir, do not try to cut my throat, because I don’t think I deserve dying so young. I am a doctor, a physician. I was born in the United States, a country where doctors are held in high esteem and usually do not get involved in crimes. On the contrary, they are always ready to help people. For instance, you have a skin condition that I suspect to be basal cell carcinoma. In simple terms, you have cancer, but not a dangerous and aggressive kind of malignancy. I can heal you.”
The talk about cancer was contrived in order to gain time. I could not diagnose cancer through a glimpse from two meters away, let alone classify the disease as basal cell carcinoma. However, if the man were to buy my talk, I could fake a medical procedure and try to win his good will. At the very least, I could divert his attention long enough for a quick escape. Unfortunately he seemed too stupid to understand the meaning of carcinoma. Anyway, without waiting for his reaction to my words, I kept my eyes on him, while stepping backwards, in the direction of the stern. However, I was so unfortunate that I tripped on that kind of step produced through those differences that often exist between the prow and the stern of a deck. I tripped and fell on my back.
The first thing that a retreating person thinks when she or he falls back is to prop on both hands to get up. This strategy is dangerous, since it precludes the use of hands for defense or attack. Therefore, practitioners of Brazilian Jiu Jitsu developed techniques for taking the fight to the ground. I learned these techniques while still at Logan, but they proved to be ineffective on this particular occasion, since my opponent did not make any gesture towards attacking me. He merely shouted orders to his granddaughter. “Darling, could you bring my shotgun here? It is fixed on the wall, above my bed.”
Masters of Brazilian Jiu Jitsu never told me anything about shotguns. Then I forgot their excellent lessons, turned by back to the boat dweller, raised on my foot and started the six meters that separated me from the stern. Of course, I am not sure about the distance that separated me from the stern and safety. Probably I would not be safe even after jumping out of the boat, since the crowd in front of the movie theater could side with the boat dweller. In any case, when I was making the final steps to the stern, my way was interrupted by the presence of two uniformed men blocking my way.
The policemen seemed to be more interested in the boatman than in me. Therefore, it was to my enemy that one of the policemen, a tall European looking fellow, said: “So, did you kill the Bolivian? I mean, the Bolivian policeman who was found floating down the river, with large patches of missing hair.” The other policeman, a short and stout mulatto complemented the thought: “I wondered who would kill a man to steal his hair. Now I have a good explanation for the event.”
One thing that I learned from Brazilians is to trust policemen less than gangsters. Therefore, while the two policemen were interrogating the boatman, I started to walk around them in order to escape from that ambiguous situation, where I could not tell the intent of the new arrivals. But the stout mulatto tried to interrupt my get away. “My partner and me, we just saved your balls and maybe your life. Aren’t you going to show your gratitude?” I was in Brazil long enough to know how to show gratitude, therefore I asked: “How much do you want?” The response of the police officer did not help to make the negotiations advance: “How much do you have there?”
At that moment, I saw Pülowi standing by the door of a car and frantically signaling me. I did not give further heed to the two policemen, and reached for the low rail around the stern, jumped to the sidewalk, and ran to the car. Pülowi entered the car ahead of me, slided on the seat over to the other side. With that movement, she left the open door ready for me to enter the vehicle. As soon as I was half sat, the driver accelerated the car so fast that the door closed on its own inertia.
Pülowi started a conversation in Russian to keep me a par of developments. “I guess you speak Russian, as I saw you reading a novel by Boris Akunin on your Kindle. When I hired this fake taxi driver, I pretended not to know Portuguese or Spanish. Therefore, when he hears us speaking Russian, he probably will think that we are conversing in an Indian language, such as Quechua. I would doubt very much that he can tell the difference between Russian and Quechua. The point is that we are not safe yet, since this man clearly intends to steal your money and rape me. He avowed these plans to his companions, since he thought that I could not understand what he was saying. Therefore, whatever he does, don’t react. Let me handle the situation. My job is to get you safe to Raposa do Sol, so don’t let your amateurish maneuvers make this task harder than it already is.”
The street along the banks of the river ended at a glade that grazing animals had cleared in the forest. The driver stopped the car and told me: “Start walking, leave the little Chinese girl entrusted to my care.” People in Brazil often confuse native Indians with Chinese or Japanese, since they display oriental features.
The assassin spoke in coloquial Portuguese, when he made the suggestion that I should depart and leave Pülowi behind. However, he was not sure that I could understand Portuguese. Therefore he made his meaning clear with a Glock pistol that he brandished, using the weapon to make a gesture in the direction of a single line track that penetrated into the forest.
I am not brave enough to face an armed drug trafficker. Even so, I did not hide myself in the forest, as the fake driver suggested. In fact, I stayed put, in doubt about what to do. Even if I would be coward enough to run into the wood, after raping the girl, the ruffian would remember that I could be carrying money. In that case, he would chase me and kill me easily, since he knew the land. Evasion was not a good option for an intelligent coward, like myself.
After suggesting me the way into the woods, the bully focused his attention on Pülowi. Initially, he pointed the gun on her head, in order to bend the girl to his will. Then he probably concluded that a gun was an excessive resource for taming a young woman, and it could get in his way during the rape. I could infer that the man concluded that a gun was not necessary for the task at hand, because he dropped the pistol on the ground. I immediately thought that an opportunity could arise, where my taking hold of the pistol could be attainable, when the rapist started doing what rapists do best.
I cannot remember what plans I had created in my mind for wrestling the gun away from the thug. In any case, my plans did not come to bear. As soon as the rapist dropped his pants, the girl drew a knife from a sheath on her lower left leg and cut his penis off. The proceeding stage of Pülowi’s master plan was to get hold of the gun. Upon doing so, she liberated the wounded man from his misery by shooting him in the head.
I followed the wild woman in silence to wherever she wanted to lead me. We followed the river downstream through the dense forest until we found a motorized boat hidden among the canopies of the low lying trees that grew on adjacent swampland. It seems that Pülowi left that boat there a few days before for the sole purpose of providing us a quick getaway.
Pülowi piloted the boat to a much bigger town, with well constructed and conserved buildings. There were many warehouses and illegal sawmills built in their essence from premolded concrete. The Indian girl guided me to a two floor office facility. Only one of the offices was occupied, and even here there was a lone middle aged man, who was sat in a very comfortable chair behind a desk. The girl and me stood, as there were no additional chairs for possible visitors.
The Indian girl told the owner of the establishment: “Here is your man, safe and sound as I had promised you. I hope that my payment has been transfered to my account in Colombia.”
“I still need your services, young woman, and as long as I need you, be rest assured that I will deposit your money as agreed. Do you need ready cash for your trip back home?”
“I am not crazy enough to carry cash on me in such a place. When I need something, such as food and tools, I prefer to steal or rob, instead of drawing attention to myself by paying in cash for an item and showing everybody that their attack on me could be profitable.”
“Since you are satisfied that matters between us are settled, you can leave me with the doctor to talk business.”
I thought that the man behind the desk was some sort of government officer in charge of administrating the Indian reservation. Therefore, I asked him when I would depart for the Indian village, where I was supposed to work.
“There is no Indian village. In fact, there is no Pirunucu tribe. The bureaucrats in Brasilia created many fictional towns and villages for bogus medical positions. Politicians and fake entrepreneurs keep half of the payment that should go to the doctors in charge of inexistent practices. The doctors themselves receive the other half for doing nothing, which is a good deal for everybody!
“Creating fake ids or borrowing the id from a dead person is a common practice in Brazil. For instance, crooks often claim that a deceased person is alive to collect benefits from social security or medical insurance companies. In practice, long after the death of the client, hospitals and lawyers keep collecting pension checks, benefits and payments for providing health care. The case of Mais Medicos is interesting, because the swindlers have created whole tribes, towns and cities for embezzling money. However, this is by no means the largest scheme for stealing public money! For example, the supplying of water to urban populations provided interesting opportunities for corrupt politicians to rake off some good cash.
“The most notorious case of such schemes to earn money with water transference projects, which in fact deliver little or next to nothing of the promised resource, is the transference of water from the San Francisco River to smaller streams in the Northeast of Brazil. The civil engineering works should have taken at least 10 years. The fake engineering firms asked for two billion dollars in small installments for completing the project, only to revise the value upward to 4 billion, when arriving at the deadline of completion. It is pointless to say that at the deadline there were no channels to speak of. The make-believe engineers counted on time for removing the necessity of accountability: In ten years, honest engineers and politicians involved in the project would be dead from natural causes, killed or removed from the political process, and the surviving engineers and corrupt politicians would have time for making the money untraceable. The other possibility is that the incumbent government would go bankrupt and stop paying the installments, which would provide a good excuse for interrupting the works, thus keeping the amount already paid.
“In this town of ours, the world and his wife are organizing schemes for accumulating wealth. There are people who are chopping down the forest to obtain wood, which will worsen global warming, but not before making the criminals rich from selling the wood to furniture manufacturers in Denmark. There are also people that are mining gold in the Indian reservations, which is by the way illegal. I represent the miners and panners. Since I am not half as bad as many of the criminals here, I saw to it that the Indians receive their fair share of the criminal operation. I am talking about real Indians, flesh and blood human beings, not imagined tribes, such as the Pirunucus. These Indians do need physicians and dentists, and have the money to pay you. What do you think about working for my Indians? Not that I care about these Indians, but they have low immune resistance to European infectious diseases. If all of them die from the contact with civilization, squatters will occupy their land, and I will not have the monopoly of buying the gold that belongs to them.”
“If what you are telling me is true, I am involved in a criminal scheme, and I will denounce it to the authorities.”
I must reveal a few things about myself. The first revelation is that I am not like Archie Goodwin. This means that I cannot reproduce a conversation verbatim. For those of you who do not know who is Archie Goodwin, Rex Stout wrote many books about an old man, Nero Wolfe, who was so fat that he rarely left his brownstone house voluntarily. Therefore, he spent a lot of money to make his home amenable to all his needs, hobbies, desires, impulses and cravings. One of his passions was eating, the other was orchids, in that order. Therefore, he hired a Swiss chef and a German gardener. Of course, the Swiss chef was born in that region of Switzerland, where the locals speak French. It was in French that Nero Wolfe discussed the everyday menu with Fritz, this is the name of the Swiss chef.
In September 1934, Nero Wolfe left his home willingly for the privilege of dining at the same table as Albert Einstein. I guess that he accepted the invitation not because he would sit with Einstein, but because the food was good.
How could Nero Wolfe manage to sustain such an expensive life style? Well, he owned a detective agency, where the only fixed employee was Archie Goodwin. The peculiar ability of Archie Goodwin in repeating conversations verbatim came to my mind because the top of the desk was full of books on Nero Wolfe. The man in front of me certainly was fond of tales about the obese bon vivant. However, let us return to that strange office with only two pieces of furniture, a desk and a chair. Before this long digression, where I explained who Archie Goodwin was, this report came to a stop at the point, where I was strongly putting the case to my host of the need to inform the authorities about this scheme for hiring fake physicians.
“I repeat, it seems that I became one of the victims of a criminal scheme for hiring unscrupulous doctors. The authorities must be told ofthis embezzlement of public funds.”
“From your choice of vocabulary, gestures and tone of voice, I got the impression that you believe that I am part of these criminal activities. I can also infer that you are a newcomer to Brazil, since you believe that the local authorities are engaged in crime fighting operations in the broader sense. This may be true, if the criminals are disrupting crimes committed by the authorities themselves, such as corruption, misconduct, passing legislation without rising above self-interest, overpricing, report falsification and fake bids. I could keep on listing the different transgressions of the laws of the land and crimes against humanity that Brazilian authorities have devised to increase their income or for a comfortable retirement plan in Paraguay. Unfortunately, I am not sure whether the English language has all the technical words for describing the variety of unlawful acts that Brazilian public officers commit on a daily basis.
“You need to wise up. For instance, did you notice that there is no chair for visitors in my office? The reasons for a person coming to me are many. Very few people enter through that front door, in order to propose a mutually beneficial deal, but given the opportunity through a lapse on my part, they will force the tide to turn in their favor. A slightly larger class of callers want to profit at my expense. Finally, there is a large group of men and women that appear with the clear intention of killing me or taking me for everything they can.
“In any case, when you say that you will report the misappropriation of public funds, you sound as you were threatening somebody. Since I am the only person in this room, it seems as though your threat is aimed at me. The fact is that I have nothing to do with this health scam. I found out that it existed through pure chance. When people in Brasilia discovered that you would come here to take up a doctor’s position for an inexistent tribe, they decided it would be best to kill you, since you could call public attention to what they are doing. As things stand, the criminals do not have operatives in this part of the country, and so they contacted my cousin Pafuncio to do the job, who subcontracted me. I don’t know what I would do if the amount paid were large enough. However, I am a little soft and sympathize with your predicament. Therefore, I am proposing a deal, where you will do exactly what you intended to do at the start of your long wending journey to this place, to wit, provide health services to an Indian tribe.”
“Sorry for being rude. I guess I will accept your offer for no other reason than to discover a way for returning to civilization.”
“I don’t know why this place cannot be considered as civilized. Perhaps because people here prefer to do business with Indians, instead of exterminating them with the intent of bringing a doubtful brand of civilization. Don’t worry. You won’t find civilization in the abstract sense of the word, but you will enjoy all benefits of civilization. In the restaurant downtown, you can drink French wine, eat ratatouille and hear La Vie en Rose on an old jukebox. Sorry, the waiter does not speak French, only the whores do. I am not sure whether our health service is as good as in Paris, but providing health care is your job, isn’t it?”
At that moment, a blond young woman appeared behind me and poked my ribs with the muzzle of a handgun. Since I was not expecting an interruption in that strange conversation, hearing a voice behind me coupled with the poke in the ribs, really gave me a fright. The official, at least, let’s call him that, explained the situation, both to calm me and prevent the new arrival from becoming overly protective by shooting me.
“Sorry, Doctor. I called Ms Anita Nikolaisen, who will show you your accommodations, and teach you the basics of Nheengatu, that is the language spoken by the tribe where your practice will be located. To make sure that I receive what is due for my intermediary services over this whole arrangement, the hired doctor, in this case you, should double as my interpreter in my dealings with the council that governs the Indians. Therefore, it is important that you learn at least some Nheengatu with the help of Ms. Nikolaisen.”
After signaling to the blond woman that everything was fine and that I posed no threat, the man continued his rambling.
“Since I couldn’t imagine a better way of calling Ms. Nicolaisen, I pressed the panic button under the top of my desk. When Anita hears the signal from the panic button, she enters my office shooting. I raised my hand, as a signal for her not kill you. The hand signal sometimes works as intended.”
Anita continued the explanation, giving her side of the whole episode, as an excuse for her behavior toward me.
“The problem is that I did not know anything about the signal. When I received the panic signal, I thought that we were under attack. I entered here ready for shooting. What is your name? Well, Mr. Jensen, I refrained from killing you, not because of Mr. Rafael’s raised hand. For one thing, I was afraid that the bullet could hit my boss, after going through your body. Besides this, I don’t know what you carry in this suitcase, but it may be a bomb ready to explode if you drop dead and release a possible trigger that you keep pressed while you are alive and conscious. While the terrorist keeps such a trigger down, the bomb does not explode, but if an agent of law kills the fanatic, he automatically releases the trigger, and the bomb goes off. I heard that Islamic fundamentalists rely on such a device.”
“Now that I have learned of my narrow escape from death, let us discuss my wages.”
“I am afraid you didn’t understand what is going on. My business is not health care. I do not run a charity institution. I am a racketeer. The contract is very simple: You pay 20% of every penny you earn in the Indian Reservation. The value is so low, because you are going to render me invaluable services as an interpreter and bookkeeper of the gold extracted from the mines.”
“Then, how will I earn my money?”
“That is a good question. Should I answer that this is your problem? You bet I should! However, since you are a foreigner unaccustomed with the practices of the land, I will elaborate on the standard answer. The Indians have their share of the valuable minerals extracted from their land. Therefore, they can pay your fees. Then you have the gold diggers, that are stabbed from time to time. If you save the life of a stabbed man, or a shot man for that matter, you can send him a fat bill. When I say send a fat bill, I don’t mean really send a fat bill. Brazilian miners carry their valuables, such as gold nuggets, precious stones and even foreign currency in their underpants. Everybody knows that. Therefore, at airports, the first thing that a customs officer checks are the underpants of any individual suspected of smuggling money from one place to the other. Even though most people know where the valuables are, nobody steals from a wounded miner. Except his doctor and nurses of course. If you save the life of a man, you can collect some 70% of his belongings as fee. Please, collect at least 20%, that is my part of the deal. Leave him with 30% of his money or gold nuggets, for the trip back home.
“There is another way of making your stay in Brazil profitable. From time to time, French cosmetologists come to this particular region of Brazil to buy raw material for soaps, perfumes and the like from the Indians. You can intermediate the sale of such products and realize a sizable amount of euros. Don’t forget about my 20% here as well.”