proposition: Lemma swapD (p q : Plane) : swap (p+q) = swap p + swap q.
proof: Proof. by apply pair_equal_spec. Qed.
imports: axiomsKnuth mathcomp(all_ssreflect ssralg matrix ssrnum vector reals) mathcomp(normedtype order) mathcomp.algebra_tactics(ring) mathcomp.zify(zify)