Any two integers with even sum have the same parity.

$3)$ Restate the claim as a universally$-$quantified conditional statement.

$4)$ Set up a direct proof by generic particular.

$$ Specify your assumptions

$$ State what it's sufficient to show

$$ Discuss the next step in your proof

$5)$ Set up an indirect proof by contradiction: assumptions, need to show, next step.

$6)$ Set up an indirect proof by contraposition: assumptions, need to show, next step.