Chapter 220OptionalScaffold
XTT and Computational Bishop Sets
Prerequisites. Direct starred prerequisites: none. No later core chapter depends on this route.
Remark 220.1¶
Draft status. This chapter is a scaffold.
Opening obstruction
Cartesian cubes support paths and univalence, but a computational theory of sets asks additionally for exact equality reflection at a controlled h-level.
Development contract
Define XTT’s dimensions, coercion/composition, exact equality and universe of Bishop sets; prove canonicity at the published calculus and compare it with Cartesian cubical type theory without theorem transfer.