Professor W.M.Turski

Institute of Informatics

Warsaw University

PkiN, pok. 850

00-901 Warsaw

Poland

                                                                                                 November, 6, 1978

                                                                                                To Prof. A.P.Ershov

                                                                                                corresponding member of AS USSR

                                                                                                SB AS USSR

                                                                                                Akademgorodok, Novosibirsk

Dear Andrei!

Thank you very much for your (Knuth’s) letter! The idea of algorithmic pilgrimage is very
attractive by itself, and the list of interesting topics and (preliminary invited) persons makes it
even more attractive.

Of course, a year is a long period enough for making plans but, alas, also enough for «conditions
to be changed» (do you remember this phrase?) to the extent that possible becomes impossible
(and vice versa). In any case, if conditions are favourable, I shall go to Khorezm oasis with great
pleasure!

Two points from the list of problems (although preliminary) trouble me: I am very badly
acquainted with original works by Al-Khorezmi and I cannot imagine how knowledge can be
expressed via algorithms. If «knowledge» is understood in the broad sense, including a skill in
doing something, then I more or less imagine the matter, but if «knowledge» is taken in the
narrow sense (as what is stored in the Big Soviet Encyclopedia, for example), then it’s not quite
clear for me.

Surely, all these «stirring» problems are the very essence of the proposed meeting!

In any case (i.e., not depending on whether I can come or not), thank you once more for your
preliminary invitation and wish you success: the idea is beautiful!

                                                                                                Best regards,

                                                                                                your ......