Theorem iexie ≪ | index | src | ≫

theorem iexie {x: nat} (a: nat) (b: wff x): $ x = a -> b $ > $ E. x b $;

Step	Hyp	Ref	Expression
1		hyp e	x = a -> b
2	1	anwr	T. /\ x = a -> b
3	2	iexde	T. -> E. x b
4	3	trud	E. x b

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp, itru), axs_pred_calc (ax_gen, ax_4, ax_5, ax_6, ax_7, ax_12)