proposition: Lemma diag_mx_seq_taker m n (s : seq R) : diag_mx_seq m n (take n s) = diag_mx_seq m n s.
proof: Proof. apply/matrixP=> i j; rewrite !mxE. by case: eqP => //=->; rewrite nth_take. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm poly mxpoly finfun tuple) mathcomp(matrix bigop zmodp polydiv) ssrcomplements dvdring