Max Operation is Commutative

Theorem
The Max operation is commutative:


 * $\map \max {x, y} = \map \max {y, x}$

Proof
To simplify our notation:
 * Let $\map \max {x, y}$ be (temporarily) denoted $x \overline \wedge y$

There are three cases to consider:


 * $(1): \quad x \le y$
 * $(2): \quad y \le x$
 * $(3): \quad x = y$

$(1): \quad$ Let $x \le y$.

Then:

$(2): \quad$ Let $y \le x$.

Then:

$(3): \quad$ Let $x = y$.

Then:

Thus $\overline \wedge$, that is $\max$, has been shown to be commutative in all cases.

Also see

 * Min Operation is Commutative