Theorem biexrexi ≪ | index | src | ≫

theorem biexrexi {x y: nat} (p: wff x) (a b: wff x y):
  $ a <-> E. y b $ >
  $ E. x (p /\ a) <-> E. y E. x (p /\ b) $;

Step	Hyp	Ref	Expression
1		hyp h	a <-> E. y b
2	1	a1i	p -> (a <-> E. y b)
3	2	biexrexa	E. x (p /\ a) <-> E. y E. x (p /\ b)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp), axs_pred_calc (ax_gen, ax_4, ax_5, ax_11)