Integrates the parallel agent work (slice computation, degeneracy
factorisation, explosion) with the normalisation implementation.
Added to DiagramMap:
- compose(): Compose two diagram maps
- has_singular_height_in_image(): Check if height is in singular image
All 77 tests pass.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Complete implementation of the zigzag normalisation algorithm from the
LICS 2022 paper "Zigzag normalisation for associative n-categories".
Key changes:
- diagram.rs: Add DiagramMap composition, singular_map extraction
- degeneracy.rs: Add extract_singular_map() and height checking functions
- normalise.rs: Complete Construction 17 with essential identity detection
The algorithm:
1. Recursively normalise at each regular height
2. Recursively normalise at each singular height with cospan leg composites
3. Assemble into intermediate diagram P
4. Remove trivial cospans (ONLY if identity AND not in sink image)
5. Compose degeneracies: d = dP ∘ dS
Critical: In dimension >= 4, some identity cospans are ESSENTIAL and must
be preserved if they are in the image of any sink map.
All 57 tests pass.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Initial structure implementing the zigzag construction for associative
n-categories (LICS 2022 paper). Includes:
- monotone.rs: MonotoneMap with Wraith's R equivalence (complete)
- zigzag.rs: Zigzag<T>, ZigzagMap<S> with composition
- diagram.rs: Diagram, DiagramN, Cospan, Rewrite, Cone types
- signature.rs: Generator, Signature (complete)
- degeneracy.rs: Degeneracy detection stubs
- normalise.rs: Construction 17 algorithm structure
- typecheck.rs: Type checking against signatures
- explosion.rs: k-points and Poset for layout
- layout.rs: SpringConstraint API surface
All 33 unit tests pass.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
