Larry Wall wrote: > So here's another question in the same vein. How would mathematicians > read these (assuming Perl has a factorial postfix operator): > > 1 + a(x)**2! > 1 + a(x)²!
The "1 + ..." portion is not in dispute: in both cases, everything to the right of the addition sign gets evaluated before the addition does. As such, I'll now concentrate on the right term. As TsA pointed out, mathematicians wouldn't write the former case at all; they'd use a superscript, and you'd be able to distinguish between "a(x) to the two-factorial power" and "(a(x) squared) factorial" based on whether or not the factorial is superscripted. So the latter would be "(a(x) squared) factorial". OTOH, you didn't ask how mathematicians would write this; you asked how they'd read it. As an amateur mathematician (my formal education includes linear algebra and basic differential equations), I read the former as "a(x) to the two-factorial power": all unary operators, be they prefix or postfix, should be evaluated before any binary operator is. -- Jonathan "Dataweaver" Lang