Type
Document de travail / Working paper
Nombre de pages du document
42
Résumé en anglais
I hope the problems of the list below might be useful even for beginners,
being however open and allowing both experimental discoveries of new facts
and creation of general theories. They represent my seminar talks at Moscow in
September 2003 and at Paris in January 2004. I'm grateful to many participants
of these seminars for active work on these problems and for their help, especially
for the many remarks of F. Aicardi and of R. Uribe-Vargas, responsible for the
typing at the Paris part.
