proposition: Lemma eqd_sym : symmetric (@eqd R).
proof: Proof. by move=> a b; rewrite eqd_def; apply/andP/andP; case. Qed.
imports: HB(structures) Coq(ssreflect ssrfun ssrbool Arith.Wf_nat) mathcomp(eqtype ssrnat div seq path) mathcomp(ssralg fintype perm tuple choice generic_quotient) mathcomp(matrix bigop zmodp mxalgebra poly) stronglydiscrete