Theorem xp01disj 8529

Description: Cartesian products with the singletons of ordinals 0 and 1 are disjoint. (Contributed by NM, 2-Jun-2007.)

Assertion

Ref	Expression
xp01disj	⊢ ((𝐴 × {∅}) ∩ (𝐶 × {1o})) = ∅

Proof of Theorem xp01disj

Step	Hyp	Ref	Expression
1		1n0 8526	. . 3 ⊢ 1o ≠ ∅
2	1	necomi 2995	. 2 ⊢ ∅ ≠ 1o
3		xpsndisj 6183	. 2 ⊢ (∅ ≠ 1o → ((𝐴 × {∅}) ∩ (𝐶 × {1o})) = ∅)
4	2, 3	ax-mp 5	1 ⊢ ((𝐴 × {∅}) ∩ (𝐶 × {1o})) = ∅

Syntax hints:   = wceq 1540   ≠ wne 2940   ∩ cin 3950  ∅c0 4333  {csn 4626   × cxp 5683  1_oc1o 8499

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-11 2157  ax-12 2177  ax-ext 2708  ax-sep 5296  ax-nul 5306  ax-pr 5432

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1543  df-fal 1553  df-ex 1780  df-sb 2065  df-clab 2715  df-cleq 2729  df-clel 2816  df-ne 2941  df-ral 3062  df-rex 3071  df-rab 3437  df-v 3482  df-dif 3954  df-un 3956  df-in 3958  df-ss 3968  df-nul 4334  df-if 4526  df-sn 4627  df-pr 4629  df-op 4633  df-br 5144  df-opab 5206  df-xp 5691  df-rel 5692  df-cnv 5693  df-suc 6390  df-1o 8506

This theorem is referenced by:  endisj  9098