The logic species a predicate answers in: its own, when it names one (IsSpeciesTaggedArrow), else the species of its answer type, and a composite the species of its last arrow. No type where none applies (a substitution failure, not an error). The lattice nodes over arrows and the combinators and Subobject (:topoi) read this, so a Chain<int> set (answer int, species Chain<int>) conjoins in Chain<int>, and a set pulled back along an arrow (a cylinder, χ ∘ π) answers in the set's species. More...

Detailed Description

template<typename P>
struct dedekind::category::predicate_logic< P >

The logic species a predicate answers in: its own, when it names one (IsSpeciesTaggedArrow), else the species of its answer type, and a composite the species of its last arrow. No type where none applies (a substitution failure, not an error). The lattice nodes over arrows and the combinators and Subobject (:topoi) read this, so a Chain<int> set (answer int, species Chain<int>) conjoins in Chain<int>, and a set pulled back along an arrow (a cylinder, χ ∘ π) answers in the set's species.

The documentation for this struct was generated from the following file:

src/main/modules/dedekind/category/lattice.cppm