A decidable <= exists for the pair — generic (meet) or a per-carrier specialisation (Singleton membership, Interval endpoints). The gate for the derived relations, so they ride any <=, not only the meet-based one. More...

Concept definition

template<typename A, typename B>
concept dedekind::order::HasSubset = 
    SubobjectLatticePair<A, B> && requires(const A& a, const B& b) {
      { a <= b } -> std::convertible_to<typename A::logic_species::Ω>;
    }

Detailed Description

A decidable <= exists for the pair — generic (meet) or a per-carrier specialisation (Singleton membership, Interval endpoints). The gate for the derived relations, so they ride any <=, not only the meet-based one.