Surely we accept unary minus as one of our functions? Once we accept one unary function we're just quibbling over details. I agree that you need to define and

Surely we accept unary minus as one of our functions? Once we accept one unary function we're just quibbling over details. I agree that you need to define and agree upon a finite set of allowed operations before playing the game. IMHO, square root, logarithm/exp, floor/round/ceiling, sin/cos/tan ought to be included in the list. But that's just like, my opinion, man.