Theorem elabed2 | index | src |

theorem elabed2 (A: set) (G: wff) (a: nat) (q: wff) {x: nat} (p: wff x):
  $ G /\ x = a -> (p <-> q) $ >
  $ G -> A == {x | p} -> (a e. A <-> q) $;
StepHypRefExpression
1 hyp e
G /\ x = a -> (p <-> q)
2 1 bieq2d
G /\ x = a -> (a e. A <-> p <-> (a e. A <-> q))
3 2 bi1d
G /\ x = a -> (a e. A <-> p) -> (a e. A <-> q)
4 3 elabed1
G -> A == {x | p} -> (a e. A <-> 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), axs_set (elab, ax_8)