Theorem nfxp ≪ | index | src | ≫

theorem nfxp {x: nat} (A B: set x):
  $ FS/ x A $ >
  $ FS/ x B $ >
  $ FS/ x Xp A B $;

Step	Hyp	Ref	Expression
1		hyp h1	FS/ x A
2		hyp h2	FS/ x B
3	1, 2	nfxab	FS/ x X\ y e. A, B
4	3	conv Xp	FS/ x Xp A 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_10, ax_11, ax_12), axs_set (elab, ax_8)