proposition: Lemma or12_equiv: forall A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 , or12 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 <-> A1 \/ A2 \/ A3 \/ A4 \/ A5 \/ A6 \/ A7 \/ A8 \/ A9 \/ A10 \/ A11 \/ A12 .
proof: Proof. intros. split. intros H. rewrite <- or11_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. left. exact H. constructor 11. right. exact H. intros H. destruct H. constructor 1. exact H. rewrite <- or11_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. Qed.
imports: Coq(Setoid Morphisms)