Theorem elsep | index | src |

pub theorem elsep (n: nat) (A: set) (a: nat):
  $ a e. sep n A <-> a e. n /\ a e. A $;
StepHypRefExpression
1 bitr
(a e. sep n A <-> a e. n i^i A) -> (a e. n i^i A <-> a e. n /\ a e. A) -> (a e. sep n A <-> a e. n /\ a e. A)
2 ellower
finite (n i^i A) -> (a e. lower (n i^i A) <-> a e. n i^i A)
3 2 conv sep
finite (n i^i A) -> (a e. sep n A <-> a e. n i^i A)
4 finss
n i^i A C_ n -> finite n -> finite (n i^i A)
5 inss1
n i^i A C_ n
6 4, 5 ax_mp
finite n -> finite (n i^i A)
7 finns
finite n
8 6, 7 ax_mp
finite (n i^i A)
9 3, 8 ax_mp
a e. sep n A <-> a e. n i^i A
10 1, 9 ax_mp
(a e. n i^i A <-> a e. n /\ a e. A) -> (a e. sep n A <-> a e. n /\ a e. A)
11 elin
a e. n i^i A <-> a e. n /\ a e. A
12 10, 11 ax_mp
a e. sep n A <-> a e. n /\ a e. A

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), axs_the (theid, the0), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)