PixelMath example not working

[gvanhau]

Hello
I was trying to learn some pixel math, so I Used the Pixel math reference.
I then intended to try the circle example

d = Abs( RDist() - 250 );
f = (1.25 - iif( d < 1.25, d, 1.25 ))/1.25;
f + (1 - f)*$target

 I get an error: (see image)

What is wrong or what has changed?
Regards
Geert

[pfile]

i think you have to declare all your variables in the expression editor. otherwise it does not know that d and f are legal "lvalues"... things that are legal to have on the left side of an equation.

[gvanhau]

yes!

Thanks