Definition:Infix Notation

Definition

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

When $\left({s, t}\right) \in \mathcal R$, we can write either:

• $\mathcal R \left({s, t}\right)$, or
• $s \mathcal R t$.

The notation $s \mathcal R t$ is known as infix notation.

Sources

• H. Jerome Keisler and Joel Robbin: Mathematical Logic and Computability (1996): $\S 2.2$