Complex sentence: One of the founders of cybernetics, Lyapunov was member of the USSR Academy of Sciences and a specialist in the fields of real variable function theory, mathematical problems of cybernetics, set theory, programming theory, mathematical linguistics, and mathematical biology.
Split into simpler sentences: One of the founders of cybernetics, Lyapunov was member of the USSR Academy of Sciences and a specialist in the field of real variable function theory and mathematical problems of cybernetics. His main works included set theory, programming theory, mathematical linguistics, and mathematical biology.