Theorem bian22da ≪ | index | src | ≫

theorem bian22da (G a b c d: wff):
  $ G /\ d -> (a <-> b /\ c) $ >
  $ G -> (d /\ a <-> d /\ b /\ c) $;

Step	Hyp	Ref	Expression
1		anass	d /\ b /\ c <-> d /\ (b /\ c)
2		hyp h	G /\ d -> (a <-> b /\ c)
3	2	aneq2da	G -> (d /\ a <-> d /\ (b /\ c))
4	1, 3	syl6bbr	G -> (d /\ a <-> d /\ b /\ c)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)