proposition: Lemma T1graph_p3 x (H:inc x T1graph) (Ha:= proj32 (T1graph_p2 H)) (Hb:= proj33 (T1graph_p2 H)): ((Bo Ha) <= (Bo Hb))%ca.
proof: Proof. apply/(T1graph_o1 Ha Hb); rewrite ( proj31 (T1graph_p2 H)). by move /setI2_P : (H) => []. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)