Suppose A = CB and A, C, and B are positive real numbers and C < 1. It must be so that A < B. Suppose instead that C > 1; then A > B. The inequalities are reversed (so that A > B and A < B, respectively) if we instead say that A and B are negative real numbers (C still being positive).

If what I am saying is true, what is this axiom or rule called?