ETCS-aligned upper bound for meet/intersection cardinality. More...

Concept definition

template<typename S>
concept dedekind::sets::HasUpperBound =  requires(const S& s) {
  { s.upper_bound() } -> std::convertible_to<std::size_t>;
}

Detailed Description

ETCS-aligned upper bound for meet/intersection cardinality.

For extensional sets with explicit upper_bound(), this is min(bound(A), bound(B)). If exactly one operand provides an explicit finite bound, that bound is still a valid upper bound for the meet. For fully intensional/transfinite pairs where neither side exposes upper_bound(), the function returns the maximal finite sentinel.

A set with an explicit finite bound: upper_bound() is formed and converts to std::size_t.

Template Parameters

S the set.