Receipt knot algebra — design note

Source artifact UNAVAILABLE in this repository

The migrated page formerly called upstream code runnable “in this repo,” but the referenced code tree is not present in docs-site and no immutable szl-cookbook revision is pinned here.

The knot analogy treats receipt-chain transformations as candidate equivalences. It is a modeled reasoning device until exact definitions, executable code, and theorem statements are supplied.

Required closure

1. Pin the upstream source repository to a full commit.
2. Name and hash every input fixture.
3. Execute the implementation and retain output/test evidence.
4. Cite exact Lean theorem names and distinguish open obligations.
5. Use pinned receipt fixtures; a11oy live receipt retrieval is currently UNAVAILABLE.

Reidemeister-style invariance is not inferred from a diagram. Until those gates close, this recipe is MODELED / SOURCE_UNAVAILABLE.