Theorem xabeq2d ≪ | index | src | ≫

theorem xabeq2d (_G: wff) {x: nat} (A _B1 _B2: set x):
  $ _G -> _B1 == _B2 $ >
  $ _G -> X\ x e. A, _B1 == X\ x e. A, _B2 $;

Step	Hyp	Ref	Expression
1		eqsidd	_G -> A == A
2		hyp _h	_G -> _B1 == _B2
3	1, 2	xabeqd	_G -> X\ x e. A, _B1 == X\ x e. A, _B2

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_10, ax_11, ax_12), axs_set (elab, ax_8)