[math-fun] Terminology

When I first learned the rigorous definition of a function f: X -> Y, the terminology was unequivocal: X is the domain of f, and Y is the range of f. The latter is unconditionally the case, irrespective of whether f is onto. Nowadays, so many high school course and ill-considered calculus texts have redefined "range" to mean f(X) -- what I was taught is called the image of f -- that in teaching I've leaned away from using the word range to mean either thing. Now I call the classical range by the term "codomain" (and I still call image "image"). It's a shame when the cognoscenti feel obliged to follow the ignorami. --Dan