Which $of$ the following equations does NOT represent a function?

$($

$x$

$,$

$y$

$)$

:

$y$

$3$

$=$

$x$

$(x,y)$:$y$

$3$

$=x$

$($

$x$

$,$

$y$

$)$

:

$y$

$=$

$x$

$3$

$(x,y)$: $y=x$

$3$

$($

$x$

$,$

$y$

$)$

:

$y$

$3$

$=$

$x$

$3$

$(x,y)$:$y$

$3$

$=x$

$3$

$($

$x$

$,$

$y$

$)$

:

$|$

$y$

$|$

$=$

$x$

$3$

$(x,y)$:$|y|=x$

$3$