Theorem bian1rexi ≪ | index | src | ≫

theorem bian1rexi (b: wff) {x: nat} (p a c: wff x):
  $ a <-> b /\ c $ >
  $ E. x (p /\ a) <-> b /\ E. x (p /\ c) $;

Step	Hyp	Ref	Expression
1		hyp h	a <-> b /\ c
2	1	a1i	p -> (a <-> b /\ c)
3	2	bian1rexa	E. x (p /\ a) <-> b /\ E. x (p /\ c)

Axiom use

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