@hackage involutive-semigroups0.1.0.0

A semigroup S is said to be with involution if it comes equipped with an "inverse-like" operation rev. Specifically, the following must hold for all x y : S:

• rev (rev x) = x
• rev (x <> y) = rev y <> rev x.

reverse is the prototypical example. Any group inverse automatically satisfies these laws.