By the same reasoning, divisibility does not use divisibility. Instead of asking if x is divisible by y you create a set of all products of the form ny where n

By the same reasoning, divisibility does not use divisibility. Instead of asking if x is divisible by y you create a set of all products of the form ny where n is an integer, then check to see if x is a member of that set. I don't buy it. qt = sp looks too much like x = ny to me.