Managing Proof Documents for Asynchronous Processing

Asynchronous proof processing is a recent approach at improving the usability and performance of interactive theorem provers. It builds on a simple metaphor: the user edits a proof document while the prover checks its consistency in the background without explicit requests from the user. This paper presents a software architecture for asynchronous proof processing. Its foundation is a novel state model for commands that synchronizes the possibly parallel accesses of the user interface and prover. The state model is complemented by a communication protocol that places minimal requirements on the prover. The model also allows asynchronous processing to be emulated by existing linear-processing proof engines, such that the migration to the new communication protocol is simplified. A prototype implementation that works with the current development version of Isabelle is presented.