Theorem sbethh | index | src |

theorem sbethh (a: nat) {x: nat} (p q: wff x):
  $ F/ x q $ >
  $ p $ >
  $ x = a -> (p <-> q) $ >
  $ q $;
StepHypRefExpression
1 hyp h
F/ x q
2 hyp e
x = a -> (p <-> q)
3 1, 2 sbeh
[a / x] p <-> q
4 hyp hp
p
5 4 sbth
[a / x] p
6 3, 5 mpbi
q

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp, itru), axs_pred_calc (ax_gen, ax_4, ax_5, ax_6, ax_7, ax_10, ax_11, ax_12)