Monoid
A monoid is a really simple concept which consists of a pair of set of objects
\(S\) and a binary operator \(\cdot\) defined on them, such that
- There exists an identity (\(id \in S\)) such that \(a \cdot id = id \cdot a = a\) for all \(a \in S\)
- The binary operator \(\cdot\) is associative i.e. \(a \cdot (b \cdot c) = (a
\cdot b) \cdot c\) for all \(a, b, c \in S\)
Interesting note: Klesli Category can also be seen as a monoid with
it’s morphisms as objects.