It's roughly the right word for it - mathematicians would say that operations f and g commute if f(g(x)) = g(f(x)) for all x. In this specific case it is not qu

It's roughly the right word for it - mathematicians would say that operations f and g commute if f(g(x)) = g(f(x)) for all x. In this specific case it is not quite true that (^4) and (%15) commute, but if we treat (%15) as returning an element of the-integers-modulo-15 then it is true that the two operations precisely commute. (I think people would say "they commute" anyway, because colloquially it's close enough).