Use named operators consistently.
Use code instead of Latex in Comparable laws.
Sandbox: think about ways to provide defaults for Comparable
Replace defaults for Comparable by a smarter predicated instance.
Explicitly convert Integrals to their underlying type in constexpr contexts.
Logical: remove obsolete workaround
StdArray: use equal instead of == in tests
Orderable: add a default instance
Sandbox: Remove obsolete Comparable experiments.
Integral: Remove redundant operators