Oleg Fedorovich Serebryannikov, whose scientific career was carried out
at the University of Saint-Petersburg, died in 1991. He was especially interested
in heuristic problems and principles of mathematical problems solving and in
their connection with methods of formal deduction. In his technical research, he
was noted for his work on normalization proofs, that is for proofs of cutelimination,
or normal form theorems, for Gentzen-type calculi, and for modal
logics, such as the systems S4.2 and S5.