fact: Definition find2 m n (A : 'M[E]_(m.+1, n.+1)) (v : E) : option ('I_m.+1 * 'I_n) := pick [pred ij | ~~(v %| A ij.1 (lift 0 ij.2))] .
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)