PLEASE:Predictable Logic based ExecutAble SpeCifications

Abstract

PLEASE is an executable specification language which supports program development by incremental refinement. Software components are first specified using a combination of conventional programming languages and mathematics. These abstract components are then incrementally refined into components ill an implementation language. Each refinement is verified before another is applied; therefore, the final components produced by the development satisfy the original specilieations. PLEASE allows a procedure or function to be specified using pre-and post-conditions written in predicate logic and all abstract data type to have a type invariant. PLEASE specifications may be used in proofs of correctness, and may also be transformed into prototypes which use Prolog to "execute" pre-and post-conditions. The early production of executable prototypes for experimentation and evaluation may enhance the development process.

An overview and bibliography of ENCOMPASS

“…[6,8,12,13,15,17,19] family of wide-spectrum, executable specification languages. The basic idea behind PLEASE is to execute pre-and post-conditions using logic programming techniques.…”