# Definition:Subsignature/Supersignature

## Definition

Let $\mathcal L, \mathcal L'$ be signatures for the language of predicate logic.

Let $\mathcal L$ be a subsignature of $\mathcal L'$.

Then $\mathcal L'$ is said to be a supersignature of $\mathcal L$, denoted:

$\mathcal L' \supseteq \mathcal L$