User:Jshflynn/Definition:Subalphabet product

Definition

Let $\Sigma$ be an alphabet and $\circ$ denoted concatenation.

Let $V$ and $W$ be subalphabets of $\Sigma$.

Then the subalphabet product (under concatenation) of $V$ with $W$ is denoted $VW$ and defined:

$VW = \{v \circ w: v \in V \land w \in W \}$