Definition:Dual Relation/Complement of Inverse

Definition
Let $\mathcal R \subseteq S \times T$ be a binary relation.

Then the dual of $\mathcal R$ is denoted $\mathcal R^d$ and is defined as:


 * $\mathcal R^d := \overline{\left({\mathcal R^{-1}}\right)}$

where:
 * $\mathcal R^{-1}$ denotes the inverse of $\mathcal R$
 * $\overline{\left({\mathcal R^{-1}}\right)}$ denotes the complement of the inverse of $\mathcal R$.