xLaDe

Lean 4 proofs break silently across versions. Projects built on Lean drift from upstream until one day they simply stop working. Nobody knows why. These are not edge cases. They are the normal experience of working with a proof assistant under rapid development.

xLaDe is a research platform that studies these problems and builds tooling to address them. It is not a theorem library, a fork of Lean, or a replacement for any existing tool. It is an ecosystem layer — a controlled environment for running experiments on how Lean is used, enforcing architectural boundaries that prevent kernel drift, and recording enough metadata to reproduce any experiment correctly, years later.

xLaDe is built primarily as a command-line tool for Linux, with tested support for Windows (via WSL) and Android (via Termux). It installs through pip, ships with a comprehensive test suite and remains experimental.