Chapter 221OptionalScaffold
Parametric Cubical Type Theory and HIT Free Theorems
Prerequisites. Direct starred prerequisites: Chapter 60. No later core chapter depends on this route.
Remark 221.1¶
Draft status. This chapter is a scaffold.
Opening obstruction
Cubical paths internalize equality while parametric bridges require an affine dimension discipline; identifying the dimensions destroys one of the needed structural laws.
Development contract
Freeze the two-dimensional Path/Bridge/Gel/extent syntax, prove Cavallo–Harper relativity and the binary smash-product free theorem, and build the book-owned affine-dimension checker. The source’s incomplete Bridge/Gel presheaf and Kan obligations are excluded rather than printed as a proof.