John Backus. The Algebra of Functional Programs: Function Level Reasoning, Linear Equations, and Extended Definitions. In Josep Díaz, Isidro Ramos, editors, Formalization of Programming Concepts, International Colloquium, Peniscola, Spain, April 19-25, 1981, Proceedings. Volume 107 of Lecture Notes in Computer Science, pages 1-43, Springer, 1981.
Abstract is missing.