Definition:Inverse Entourage

Definition
Let $S$ be a set.

Let $\UU$ be a quasiuniformity on $S$.

Let $u \in \UU$ be an entourage of $\UU$.

Then the inverse entourage $u^{-1}$ is defined as:
 * $u^{-1} := \set {\tuple {y, x}: \tuple {x, y} \in u}$

Also see

 * Definition:Inverse Relation, which is consistent with this definition.