Definition:Way Above Closure

Definition
Let $\left({S, \preceq}\right)$ be an ordered set.

Let $x \in S$.

The way above closure of $x$, denoted by $x^\gg$, is defined by:
 * $x^\gg := \left\{ {y \in S: x \ll y}\right\}$

where $\ll$ denotes the way below relation.