proposition: Lemma cone_target_fiprod_cone : forall a u v y1 y2, cone_target (fiprod_cone a u v y1 y2) = a.
proof: Proof. ir. uf cone_target. rw socle_fiprod_cone. rww target_vee_functor. Qed.
imports: Arith colimits little_cat fc_limits cardinal