proposition: Lemma mor_twoarrow_cat_or : forall u, mor twoarrow_cat u = (u = (catyd_arrow i1') \/ u = (catyd_arrow i2') \/ u = (catyd_arrow a0') \/ u = (catyd_arrow a1')).
proof: Proof. ir. ap iff_eq; ir. ufi twoarrow_cat H; rwi mor_catyd H; nin H. nin x. or_show 0; am. or_show 1; am. or_show 2; am. or_show 3; am. ap twoarrow_data_property. cp twoarrow_data_property. nin H. rw H. uf twoarrow_cat. app mor_catyd_catyd_arrow. nin H. rw H. uf twoarrow_cat. app mor_catyd_catyd_arrow. nin H. rw H. uf twoarrow_cat. app mor_catyd_catyd_arrow. rw H. uf twoarrow_cat. app mor_catyd_catyd_arrow. Qed.
imports: Arith cat_examples cardinal fc_limits