Automatic Verification of TLA + Proof Obligations with SMT Solvers

TLA is a formal specification language that is based on ZF set theory and the Temporal Logic of Actions TLA. The TLA proof system tlaps assists users in deductively verifying safety properties of TLA specifications. tlaps is built around a proof manager, which interprets the TLA proof language, generates corresponding proof obligations, and passes them to backend verifiers. In this paper we present a new backend for use with SMT solvers that supports elementary set theory, functions, arithmetic, tuples, and records. Type information required by the solvers is provided by a typing discipline for TLA proof obligations, which helps us disambiguate the translation of expressions of (untyped) TLA, while ensuring its soundness. Preliminary results show that the backend can help to significantly increase the degree of automation of certain interactive proofs.