Evaluation criteria
\E x \E y \bl %m(x) != %m(y)\E x \E y \bl %m(x) = %m(y)\E x \E y \bl y /\ %m(x) != %m(y)\A x \A y \bl fun(x) = fun(y) \not\Rightarrow %m(x) = %m(y)\A x \A y \bl %m(x) <= %m(x + y) & %m(y) <= %m(x + y)\A x \A y \E z \bl %m(x) = %m(y) /\ %m(x + z) != %m(y + z)\E x \E y \bl %m(x) + %m(y) < %m(x + y)