This question uses the following syntax: ParametricPlot[{x, y}&&(x<y), {x, 0, 1}, {y, 0, 1}] Is this documented anywhere? Why does it work (is it a weird side effect I'm not realizing)?
@Szabolcs Makes sense to me (if a bit weird way to do it). As plotpoints goes up, resolution of hypotenuse increases as an aside. In any case, the evaluations for the plot produce a sequence that when fed to ListPlot generates the same result, though obviously with no concept of the "region" and concomitant filling...