Definition monotone1 T0 (gf: rel1 T0 -> rel1 T0) :=
  forall x0 r r' (IN: gf r x0) (LE: r <1= r'), gf r' x0.

Theorem paco1_mult_strong: forall r, paco1 gf (upaco1 gf r) <1= paco1 gf r.