proposition: Lemma find1P m n (A : 'M[E]_(m.+1, n.+1)) (v : E) : pick_spec [pred i | ~~(v %| A (lift 0 i) 0)] (find1 A v).
proof: Proof. exact: pickP. Qed.
imports: mathcomp(all_ssreflect) mathcomp(all_algebra) mathcomp(all_fingroup) mathcomp(all_real_closed) CoqEAL(binetcauchy ssrcomplements mxstructure minor) CoqEAL(smith dvdring polydvd) CoqEAL(similar perm_eq_image)