Lean formalization of Eric Hehner’s aPToP, plus tools that make the book’s calculational proofs and programming notation runnable.
Three-pane assistant for calculational proofs: proof, context, suggestions — Lean kernel, no Mathlib. Book exercises in its examples picker.
Inspired by Netty, the University of Toronto prover’s assistant (named for Netty van Gasteren).
Run aPToP programming notation in the browser. Editable editor with symbols like ∧ ∨ ⇒ ⊤; Run posts to a loopback runner.
New to calculational proofs? Try the Proof Assistant tutorial: eight short lessons, each one tiny proof.
Static home from deploy/aptop/site/; /ampheck/ proxies to
a loopback Node + Lean Ampheck kernel (inspired by
Netty, the calculational
prover’s assistant designed by Eric Hehner, Robert Will, Lev Naiman, David Kordalewski
and others at the University of Toronto, named for Netty van Gasteren); /interp/ is an editable
runner (binary may be stubbed if Mathlib build is unavailable on this box).
Deploy notes: deploy/aptop/deploy.md in
tangentproofs/laptop.