Theorem con2bb | index | src |

theorem con2bb (a b: wff): $ a <-> ~b <-> (b <-> ~a) $;
StepHypRefExpression
1 con2b
(a <-> ~b) -> (b <-> ~a)
2 con2b
(b <-> ~a) -> (a <-> ~b)
3 1, 2 ibii
a <-> ~b <-> (b <-> ~a)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp)