proposition: Lemma deg_is_additive: additive deg.
proof: Proof. exact: (@lift_is_additive _ K int^o). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)