A
binary relation [math]R
[/math] on a
set [math]A
[/math] is
reflexive if
for every [math]x \href{/cs2800/wiki/index.php/%E2%88%88}{∈} A
[/math],
[math]\href{/cs2800/wiki/index.php/XRy}{xRx}
[/math].
In a picture, this means that every element of [math]A
[/math] has a self-loop: an edge back to itself.
