Theorem pimeq2i ≪ | index | src | ≫

theorem pimeq2i {x: nat} (p q1 q2: wff x):
  $ q1 <-> q2 $ >
  $ (P. x p -> q1) <-> (P. x p -> q2) $;

Step	Hyp	Ref	Expression
1		hyp h1	q1 <-> q2
2	1	a1i	T. -> (q1 <-> q2)
3	2	pimeq2d	T. -> ((P. x p -> q1) <-> (P. x p -> q2))
4	3	trud	(P. x p -> q1) <-> (P. x p -> q2)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp, itru), axs_pred_calc (ax_gen, ax_4, ax_5)