Some problems of the theory of Sobolev spaces of infinite order and of nonlinear equations. (English). In: Fučík, Svatopluk and Kufner, Alois (eds.): Nonlinear Analysis, Function Spaces and Applications, Proceedings of a Spring School held in Horní Bradlo, 1978. [Vol 1]. BSB B. G. Teubner Verlagsgesellschaft, Leipzig, 1979. pp. 23-37