That works. Personally, I’d flip flop a little:
a=numericValue(exp1.content)
b=numericValue(exp2.content)
pointlabel("A"): "${simpleFunction("\mod(a,b)")}"
More lines, but looks less complicated to me. *shrug
Also, “.content”? Normally I’d use “.latex” or just numericValue(exp1), but guess it doesn’t matter.