Semi Group

• A set (\(S\)) with an binary operation (\(\cdot\)) that is associative.

  \begin{equation*} \cdot: S \times S \to S \end{equation*}

  such that:

  \begin{equation*} \forall a,b,c \in S, a \cdot (b \cdot c) = (a \cdot b) \cdot c \end{equation*}
• An associative Magma.