Arguments rV_subP {m1 m2 n A B}.

(* Specifications: *)
Lemma row_subPn m1 m2 n (A : 'M_(m1, n)) (B : 'M_(m2, n)) :
reflect (exists i, ~~ (row i A <= B)%MS) (~~ (A <= B)%MS).
Lemma rank_rV n (v : 'rV_n) : \rank v = (v != 0).
Lemma rowV0Pn m n (A : 'M_(m, n)) :
reflect (exists2 v : 'rV_n, v <= A & v != 0)%MS (A != 0).
Lemma rowV0P m n (A : 'M_(m, n)) :
reflect (forall v : 'rV_n, v <= A -> v = 0)%MS (A == 0).
Lemma submx_full m1 m2 n (A : 'M_(m1, n)) (B : 'M_(m2, n)) :
row_full B -> (A <= B)%MS.
Lemma row_fullP m n (A : 'M_(m, n)) :
reflect (exists B, B *m A = 1%:M) (row_full A).