Propositional Dynamic Logic in Lean 4

CI status

Project Goal

The aim is to prove that Propositional Dynamic Logic (PDL) has the Craig Interpolation property. The main reference is the following.

  • Manfred Borzechowski, Malvin Gattinger, Helle Hvid Hansen, Revantha Ramanayake, Valentina Trucco Dalmas, Yde Venema: Propositional Dynamic Logic has Craig Interpolation: a tableau-based proof. Preprint 2025, https://arxiv.org/abs/2503.13276

The article contains direct links to the corresponding parts of the formalization here. A checkmark in the article means that the Lean statement is sorry-free, including all its dependencies. There is no separate blueprint.

Module dependency overview

Dependency graph

(Run make dependencies.svg to update this.)

Other References