Theorem bitr2d | index | src |

theorem bitr2d (a b c d: wff):
  $ a -> (b <-> c) $ >
  $ a -> (c <-> d) $ >
  $ a -> (d <-> b) $;
StepHypRefExpression
1 hyp h1
a -> (b <-> c)
2 hyp h2
a -> (c <-> d)
3 1, 2 bitrd
a -> (b <-> d)
4 3 bicomd
a -> (d <-> b)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)