proposition: Lemma or13_equiv: forall A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 , or13 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 <-> A1 \/ A2 \/ A3 \/ A4 \/ A5 \/ A6 \/ A7 \/ A8 \/ A9 \/ A10 \/ A11 \/ A12 \/ A13 .
proof: Proof. intros. split. intros H. rewrite <- or12_equiv. destruct H. constructor 1. exact H. constructor 2. exact H. constructor 3. exact H. constructor 4. exact H. constructor 5. exact H. constructor 6. exact H. constructor 7. exact H. constructor 8. exact H. constructor 9. exact H. constructor 10. exact H. constructor 11. exact H. constructor 12. left. exact H. constructor 12. right. exact H. intros H. destruct H. constructor 1. exact H. rewrite <- or12_equiv in H. destruct H. constructor 2. exact H. constructor 3. exact H. constructor 4. exact H. constructor 5. exact H. constructor 6. exact H. constructor 7. exact H. constructor 8. exact H. constructor 9. exact H. constructor 10. exact H. constructor 11. exact H. constructor 12. exact H. constructor 13. exact H. Qed.
imports: Coq(Setoid Morphisms)