Theorem bian12d ≪ | index | src | ≫

theorem bian12d (G a b c d: wff):
  $ G -> (a <-> b /\ c) $ >
  $ G -> (d /\ a <-> b /\ (d /\ c)) $;

Step	Hyp	Ref	Expression
1		anlass	d /\ (b /\ c) <-> b /\ (d /\ c)
2		hyp h	G -> (a <-> b /\ c)
3	2	aneq2d	G -> (d /\ a <-> d /\ (b /\ c))
4	1, 3	syl6bb	G -> (d /\ a <-> b /\ (d /\ c))

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)