In order to manage to do what I intended I had to learn some little things. Still, the principal move had been given when (after a long wait that brought prices to the level I could see them. Thanks, Bill, for convincing millions of persons that they cannot live without a PC) my friend and Department colleague Genaldo Leite Nunes used the pretext of assembling my first computer to contaminate me with his enthusiasm for the Linux system and vim editor. As he is a competent mathematician (complex analysis) he could also be my guru in questions of math software and programming languages, beyond the ones of the un*x world. If these materials were mine, I would dedicate the e-book to him. But in the scale scribe – compilator - commentator – author (that I've learned from N.Postman) I stay on the level two plus epsilon; therefore the way I see to express my gratitude to him is to give him the first copy of this CD-ROM.

The close acquaintanceship with Paul James Otterson was important for me still in Fortaleza, where we had been working at UFCe – there he was my patient professor of windsurf. When the climate did not collaborate we were training the generalized windsurf (ice-cream with bananas). Later in Florianópolis he helped me many times in problems I was meeting teaching analysis – it is easy to drown in Fourier analysis but Paul swims there very well. I've always considered him a normal mathematician of the type I used to meet in Wroclaw: I could visit him at 11 p.m. asking mathematical questions, I could easily involve him in my research even though his curve of studies rarely crosses mine. Only with a passage of time I've learned that my criteria of “normality” were seldom met in Brazil.

One more thing I owe him: in a very remote past I used to read Wislawa Szymborska's column in Zycie Literackie to get indications on most surprising books that seemed to escape attention of well-informed critics. I do not know whether her column still exists but now I come close to Paul's desk and look at books of the outer layer of the heap.

Paul helps me with my hibernated English¹. He promised to correct the English version of this article. If there are any problems with language, thinking, data, just anything, please, do blame him exclusively.

I have the company of another normal mathematician here, Waldir Quandt. It is even more surprising case. I'm thinking of the bitter analysis of Richard P.Feynman of Brazilian intellectuals; having read Surely You're Joking, Mr.Feynman! I could better situate the problems that I used to encounter in dealings with my students and my colleagues. Sure, the situation of eighties and nineties is not identical to the one of fifties – but it is not so different, either. What about the brilliant scientists, like Estevão Martins de Resende from Brasília of my Department colleague, Ruy Exel? Well, they are here but it does not contradict Feynman's description. There is quite a number of these (precious) examples of individuals with universal quality and doctorates from famous institutions from abroad. But Waldir who knows perfectly English and is a sophisticated intellectual who would be comfortably integrated with my friends from Paris or Wroclaw, he had all his formal education purely Brazilian and – I believe – has never traveled to Disneyland or other cultural centers abroad. So, he is a live example that there does not exist any “Feynman's curse”; anything can go fine in this land with no transplant from abroad.

I owe to Waldir my fascination with Portuguese. He owes me several nights of work provoked by his apparently innocent geometrical questions. Our students owe both of us all those nasty moments when we permanently insist that formulating one's views (be them mathematical or not) one should pay extreme attention to the smallest elements of speech.

Compiling this collection I was thinking of our students; the library of this scope and quality can fulfill there professional needs for many years (or lives) to come; but I've also thought about these three persons. The idea was to have at least five dedicated readers – and “five” is not so small number. Where's five here? Well, Jerzy Kocik counts – as well as I.