CEGAR-PT: A Tool for Abstraction by Program Transformation

Abstraction is an important approach for proving the correctness of computer programs. There are many implementations of this approach available, but unfortunately, the various implementations are difficult to reuse and combine, and the successful techniques have to be re-implemented in new tools again and again. We address this problem by contributing the tool cegar-pt, which views abstraction as program transformation and integrates different verification components off-the-shelf. The idea is to use existing components without having to change their implementation, while still adjusting the precision of the abstraction using the successful CEGAR approach. The approach of cegar-pt is largely general: It only restricts the abstraction to transform, given a precision that defines the level of abstraction, one program into another program. The abstraction by program transformation can over-approximate the data flow (e.g., havoc some variables, use more abstract types) or the control flow (e.g., loop abstraction, slicing). To illustrate our tool, we provide a demonstration video, accessible at https://youtu.be/ASZ6hoq8asE.