# Subset Relation is Compatible with Subset Product/Corollary 2

## Theorem

Let $\left({S,\circ}\right)$ be a magma.

Let $A,B \in \mathcal P \left({S}\right)$, the power set of $S$.

Let $A \subseteq B$.

Let $x \in S$.

Then:

- $x \circ A \subseteq x \circ B$
- $A \circ x \subseteq B \circ x$

## Proof

This follows from Subset Relation is Compatible with Subset Product and the definition of the subset product with a singleton.

$\blacksquare$