Abstract

As computers are deployed in increasingly diverse, numerous, and critical roles, the need for confidence in their hardware and software becomes more acute. Often, however, computer technologies, such as programming languages, lack a sufficiently formal definition to allow rigorous mathematical analysis of their properties. Even in cases where a formal definition is available, the theorems to be proven and the definition itself tend to have many cases and many details that are easily overlooked when writing a proof by hand. This has created interest in the mechanization of the proof process through the use of automated proof assistants. In this report, we develop a formal definition for a programming language called IntegerPython, which is a subset of the Python language that supports integers, booleans, global variables, loops, modules, and nested functions. The definition takes the form of an operational semantics on a CEKS machine, which we embed in the Isabelle/HOL mechanized logic. We then prove an invariant of the CEKS machine in Isabelle/HOL. The report concludes with strategies for the efficient, executable implementation of the IntegerPython semantics and its extension into a semantics of

Citations