Theorem prelres | index | src |

theorem prelres (A B: set) (a b: nat):
  $ a, b e. A |` B <-> a, b e. A /\ a e. B $;
StepHypRefExpression
1 bitr
(a, b e. A |` B <-> a, b e. A /\ fst (a, b) e. B) -> (a, b e. A /\ fst (a, b) e. B <-> a, b e. A /\ a e. B) -> (a, b e. A |` B <-> a, b e. A /\ a e. B)
2 elres
a, b e. A |` B <-> a, b e. A /\ fst (a, b) e. B
3 1, 2 ax_mp
(a, b e. A /\ fst (a, b) e. B <-> a, b e. A /\ a e. B) -> (a, b e. A |` B <-> a, b e. A /\ a e. B)
4 eleq1
fst (a, b) = a -> (fst (a, b) e. B <-> a e. B)
5 fstpr
fst (a, b) = a
6 4, 5 ax_mp
fst (a, b) e. B <-> a e. B
7 6 aneq2i
a, b e. A /\ fst (a, b) e. B <-> a, b e. A /\ a e. B
8 3, 7 ax_mp
a, b e. A |` B <-> a, b e. A /\ a e. B

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)