16-RND(31)
(3*Y/2-X)*COS(SQR(X^2+Y^2)/5)
X-Y*SIN(X/3)
X*Y/8
ABSX-ABSY
15*COS(X/4)*SIN(Y/4)
(X^2-Y^2)/10
X*SIN(X/5-Y/4)-Y*SIN(X/4)
Y*(COS(X*Y/35)-SIN(Y/4))


The above is a list of the default 9 funtions.

You can use your own functions here (but don't change
the first one). Use appropriate scaling factors to get
optimum results.
N.B always use capital X,Y.