Final Scientific Report

Abstract : The main emphasis of grant work was bringing software that was reliably working on a DECsystem-10 into reliable operation on the Virginia Tech VM/CMS system. This work is best viewed as preparation for the substantial work of the grant. Work was also directed toward achieving two objectives: (1) Modify an incremental program verification system to accept APL programs. The main work here was to isolate code in the verifier that is specific to the syntax of the programming language in which the programs were written in a single SIMULA class so that is could be easily modified for different languages. (2) Completing the implementation of an APL expression evaluator based on a formal semantics of APL and verifying this implementation with respect to the formal semantics. During this period, the objective was to complete a verified implementation of an APL epxression evaluator and to have an interactive verifier for APL expressions working correctly by about August 15, 1980. These two pieces of software were then to be used to conduct a number of experiments that would aid in the design of a verifier for all of APL.