Semigroups
a
b
c
d
a
b
c
d
Your browser does not support the HTML5 canvas tag.
Definition:
A semigroup (S, *) is a set S with a binary operation * that satisfies the following properties:
Closure: a * b ∈ S for all a, b ∈ S.
Associativity: a * (b * c) = (a * b) * c for all a, b, c ∈ S.