PProof

Pproof is a formal verification framework and proof assistant designed to support the development, verification, and maintenance of mathematical proofs and software correctness properties. It combines an interactive proof editor with automated reasoning components to assist users in constructing formal arguments and checking their soundness.

The project originated at the PProof Project at the University of Arcadia and began in 2018, with public releases starting in 2020. It emphasizes a small verified kernel, modular extensions, and reproducible proof artifacts. The ecosystem includes a core language, libraries, and tooling for documentation and collaboration.

The architecture centers on a dependently typed core language, known as PProof Core, a bidirectionally typed calculus, and an extensible tactic language. A kernel verifies all proof objects, while automation is provided by SMT solvers and external provers. The system supports modular libraries, proof scripting, and interoperability with external environments; it can import and export proofs and supports code extraction from verified programs to functional languages such as Haskell and OCaml.

Pproof ships with a Standard Library for algebra, analysis, and formalized mathematics, and provides facilities for formal verification of software properties, including correctness proofs for algorithms and data structures. The project maintains documentation, tutorials, and a community forum to support collaboration and learning.

Critics point to a learning curve and performance considerations for large formalizations, as well as ongoing work to improve interoperability with other proof systems and to broaden library coverage.

See also: Coq, Lean, Isabelle, Agda.