Plausible

Spec sheet

Purpose

Plausible is a property testing framework for Lean 4 that integrates into the tactic framework.Read 9 Oct 2026 · github.com

Product

Plausible is a property testing framework for Lean 4 that integrates into the tactic framework.Read 8 Oct 2026 · github.com

License

The repository identifies its license as Apache-2.0.Read 9 Oct 2026 · github.com

Arbitrary instances

The README says users can derive `Arbitrary` for algebraic data types or use a top-level deriving command for multiple types.Read 8 Oct 2026 · github.com

Built-in types

The README says Plausible usually handles built-in types without additional setup.Read 8 Oct 2026 · github.com

Counterexample search

The README shows the `plausible` tactic finding a counterexample for a false property involving arrays.Read 9 Oct 2026 · github.com

Counterexamples

The README shows the `plausible` tactic finding and displaying a counterexample to a proposition.Read 8 Oct 2026 · github.com

Custom types

The README says custom types need `Repr`, `Plausible.Shrinkable`, and `Plausible.SampleableExt` instances, or `Plausible.Arbitrary`.Read 9 Oct 2026 · github.com

Deriving Arbitrary

The README documents deriving `Arbitrary` for algebraic data types, including with a top-level `deriving instance` command.Read 9 Oct 2026 · github.com

Documentation

The README directs users to the module documentation for more information.Read 8 Oct 2026 · github.com

Programmatic checking

The README shows properties being checked with `Plausible.Testable.check`.Read 9 Oct 2026 · github.com

Property checking

The README demonstrates checking a property with `Plausible.Testable.check`.Read 8 Oct 2026 · github.com

Where Specifiction places it

• Property-Based Testing Tools#25 of 286.5