proposition: Lemma filterdiff_opp (F : (V -> Prop) -> Prop) : filterdiff opp F opp.
proof: Proof. apply filterdiff_linear. by apply is_linear_opp. Qed.
imports: Coq(Reals Psatz ssreflect) Rcomplements Rbar Lim_seq Iter Hierarchy Continuity Equiv