UTPCalc - A calculator for UTP predicates

We present the development of the UTP-Calculator: a tool, written in Haskell, that supports rapid prototyping of new theories in the Unifying Theories of Programming paradigm, by supporting an easy way to very quickly perform test calculations. The emphasis during the calculator development was keeping it simple but e ective, and relying on the user to have the expertise to check its output. It is not intended to supplant existing theorem prover or language transformation technology. The tool is designed for someone who is both very familiar with UTP theory construction, and familiar enough with Haskell to be able to write pattern-matching code. In this paper we describe how this tool can be used to assist in theory development, by describing the key components of the calculator and how various aspects of such a theory might be encoded. We nish with a discussion of our experience in using the tool.