Theorem xpTd | index | src |

theorem xpTd (A B: set) (G: wff) (a b: nat):
  $ G -> a e. A $ >
  $ G -> b e. B $ >
  $ G -> a, b e. Xp A B $;
StepHypRefExpression
1 prelxp
a, b e. Xp A B <-> a e. A /\ b e. B
2 hyp h1
G -> a e. A
3 hyp h2
G -> b e. B
4 2, 3 iand
G -> a e. A /\ b e. B
5 1, 4 sylibr
G -> a, b e. Xp A 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)