proposition: Lemma prl_exa3_prop2 p: inc p r -> [/\ natp (P p), natp (Q p) & gle r (P p) (Q p)].
proof: Proof. move: prl_exa3_prop1 => [ha hb hc] pr. move: (proj31 ha _ pr) => pp; rewrite - pp in pr. by move/hc: (pr) => [hd he _]. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)