unfold MaxBank in |- *; unfold Rdiv in |- *; apply Rmult_lt_0_compat.
prove_sup.
apply Rinv_0_lt_compat; prove_sup.
unfold plat in |- *; prove_sup.
apply Rinv_0_lt_compat; apply PI_RGT_0.
Qed.

Lemma cond2_0 : (0 <= toDeg MaxBank)%R.
left; unfold toDeg in |- *; repeat simple apply Rmult_lt_0_compat.