Theorem eqab2i | index | src |

theorem eqab2i (A: set) {x: nat} (p: wff x):
  $ x e. A <-> p $ >
  $ A == {x | p} $;
StepHypRefExpression
1 hyp h
x e. A <-> p
2 1 a1i
T. -> (x e. A <-> p)
3 2 eqab2d
T. -> A == {x | p}
4 3 trud
A == {x | p}

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)