**Interactive Proof Checking**

*Thomas Reps and Bowen Alpern*

Cornell University

Knowledge of logical inference rules allows a specialized proof editor to provide a user with feedback about errors in a proof under development. Providing such feedback involves checking a collection of constraints on the strings of the proof language. Because attribute grammars allow such constraints to be expressed in a modular, declarative fashion, they are a suitable underlying formalism for a proof-checking editor. This paper discusses how an attribute grammar can be used in an editor for partial-correctness program proofs in Hoare-style logic, where verification conditions are proved using the sequent calculus.