Instead of sentence:
Given a type A, all endomorphisms defined on A are a monoid
isn't it more correct to say:
Given a type A, all endomorphisms defined on A under function composition operation are a monoid
Because semigroups are defined on pair of type A and operation on type A.
Instead of sentence:
isn't it more correct to say:
Because semigroups are defined on pair of type A and operation on type A.