Theorem eexd ≪ | index | src | ≫

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

Step	Hyp	Ref	Expression
1		nfv	F/ x a
2		nfv	F/ x c
3		hyp h	a -> b -> c
4	1, 2, 3	eexdh	a -> E. x b -> c

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp), axs_pred_calc (ax_gen, ax_4, ax_5, ax_6, ax_7, ax_10, ax_12)