Even

From CS2800 wiki


Definition: even
An integer [math]n [/math] is even if there exists [math]a \href{/cs2800/wiki/index.php/%5Cin}{\in} \href{/cs2800/wiki/index.php/%E2%84%A4}{ℤ} [/math] such that [math]n = 2a [/math].

Equivalently,

Definition: even
An integer [math]n [/math] is even if [math]n \href{/cs2800/wiki/index.php?title=%5Cequiv&action=edit&redlink=1}{\equiv} 0 \quad (\href{/cs2800/wiki/index.php?title=Mod&action=edit&redlink=1}{mod}~2) [/math].

0 is even because there exists some [math]k [/math] (namely [math]k = 0 [/math]) such that [math]0 = 2k [/math].