Fixpoint approach to the theory of computation
Zohar Manna, Jean E. Vuillemin · Communications of the ACM · 1972
Following the fixpoint theory of Scott, the semantics of computer programs are defined in terms of the least fixpoints of recursive programs. This allows not only the justification of all existing verification techniques, but also their extension to the handling, in a uniform manner of various properties of computer programs, including correctness, termination, and equivalence.