Theorem ifpeq2d ≪ | index | src | ≫

theorem ifpeq2d (_G p _a1 _a2 b: wff):
  $ _G -> (_a1 <-> _a2) $ >
  $ _G -> (ifp p _a1 b <-> ifp p _a2 b) $;

Step	Hyp	Ref	Expression
1		biidd	_G -> (p <-> p)
2		hyp _h	_G -> (_a1 <-> _a2)
3		biidd	_G -> (b <-> b)
4	1, 2, 3	ifpeqd	_G -> (ifp p _a1 b <-> ifp p _a2 b)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)