Deduce

A proof checker and small functional language for teaching logic.

Quick start

Deduce needs Python 3.12+ and the Lark parsing library. From a fresh clone:

python3 -m pip install lark
python3 deduce.py example.pf

(Use python if your system aliases that to Python 3; recent macOS and some Linux distros ship only python3. On Windows the bundled launcher is py.)

You should see:

example.pf is valid

For installation details, editor integrations, AI-assisted proof completion, and the language introduction, see Getting Started or the Deduce website.

More worked examples live in examples/.

Repo layout

• /compiler Deduce-to-C compiler (user guide)
• /docs Documentation for contributing to Deduce
• /editor Editor integrations (Emacs, VS Code)
• /examples Worked example proofs
• /gh_pages Source code for the Deduce website
• /lib Deduce library files. This includes Nat, List, etc.
• /live_code_vercel_api Source code for Deduce live code
• /logos The Hippopotamus logo and other images.
• /test Deduce files used for testing Deduce.