Now (for compiler) std::strict_weak_ordering<...> is same as std::relation<...>, and std::equivalence_relation is same as std::relation

This produces amgibuity:

#include <concepts>

#include <functional>

bool foo(std::strict_weak_order<int, int> auto x) { return true; }

bool foo(std::relation<int, int> auto x) { return false; }