Hi,

I have a lot of utility functions that I'd like to make into an Algebraic Manipulation Extras.

For example, it would be nice to have a crossMultiply:

crossMultiply[a_==b_]:=Numerator[a] Denominator[b]==Numerator[b] Denominator[a]
CreatePalette[PasteButton[crossMultiply[\[SelectionPlaceholder]]]];

This doesn't work like the Algebraic Manipulation palette: it correctly does the substitution:

a/b == c/d
crossMultiply[a/b == c/d]
a d == b c

when a/b == c/d is highlighted, but it returns the function crossMultiply[a/b == c/d] which then has to be shift/entered to evaluate.

Nothing I do can get it to evaluate automatically, which the description of PasteButton would seem to warrant. Any suggestions?

Thanks,

Eric