fact: Fixpoint trace_seqmx m (s : hseqmx m m) := match m with | O => 0%C | (S n) => (top_left_seqmx s + @trace_seqmx n (@drsubseqmx 1%N n 1%N n s))%C end.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq ssralg) mathcomp(path choice fintype tuple finset bigop poly matrix mxpoly) CoqEAL(hrel param refinements trivial_seq)