#[global]
Hint Resolve Rmult_le_compat: real.

Lemma Rmult_ge_0_gt_0_lt_compat :
forall r1 r2 r3 r4,
r3 >= 0 -> r2 > 0 -> r1 < r2 -> r3 < r4 -> r1 * r3 < r2 * r4.