No it does not express the first variable as a function of the second variable

{(2, -4)(-2, 0)(2, 2)(-2, 4)(3, -2)(-3, -2)}

Note the two blue {(2's are both first coordinates.  A function cannot
use the same first coordinate twice.

Note the two red {(-2's are both first coordinates.  A function cannot
use the same first coordinate twice.

So there are two pairs of ordered pairs that keep this from being a 
function.

Edwin