Grzegorz Bancerek wrote:
Yes, this is the same guy but his true name is Jan S'leszyn'ski.
Not exactly. He was Ukrainian. Born in Odessa. He used the first name 'Ivan' in his mathematical papers (I believe the number theory). He started to use 'Jan' when he moved to Jagiellonian Univ.
His "Teoria Dowodu'" ("Proof theory") is edited by Zaremba (from the notes of Sleszynski's lectures).
If you allow me for an anecdote:Three Polish mathematicians (not very famous but well known, the names are not important) on three different occasions told me that Sleszynski's proof of the Rolle theorem takes 600 pages. I had checked it, the book has 200 pages and the proof itself is 20 pages long. I have found later that Andrzej Mostowski on one of his lectures claimed that it is not full formalization, and if the formalization was complete that it may be, oh, even 600 pages long.
I doubt if all three of them attended the Mostowski lecture. It is just how (anti-)propaganda works.
What is important, Sleszynski believed (twenties of the previous century) that the practical formalization of mathematics is possible,
if the formalism used is properly developed. Regards, Andrzej Trybulec