Theorem in0 3317

Description: The intersection of a class with the empty set is the empty set. Theorem 16 of [Suppes] p. 26. (Contributed by NM, 5-Aug-1993.)

Assertion

Ref	Expression
in0	⊢ (𝐴 ∩ ∅) = ∅

Proof of Theorem in0

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		noel 3290	. . . 4 ⊢ ¬ 𝑥 ∈ ∅
2	1	bianfi 893	. . 3 ⊢ (𝑥 ∈ ∅ ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ ∅))
3	2	bicomi 130	. 2 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑥 ∈ ∅) ↔ 𝑥 ∈ ∅)
4	3	ineqri 3193	1 ⊢ (𝐴 ∩ ∅) = ∅

Syntax hints:   ∧ wa 102   = wceq 1289   ∈ wcel 1438   ∩ cin 2998  ∅c0 3286

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 579  ax-in2 580  ax-io 665  ax-5 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-8 1440  ax-10 1441  ax-11 1442  ax-i12 1443  ax-bndl 1444  ax-4 1445  ax-17 1464  ax-i9 1468  ax-ial 1472  ax-i5r 1473  ax-ext 2070

This theorem depends on definitions:  df-bi 115  df-tru 1292  df-nf 1395  df-sb 1693  df-clab 2075  df-cleq 2081  df-clel 2084  df-nfc 2217  df-v 2621  df-dif 3001  df-in 3005  df-nul 3287

This theorem is referenced by:  0in  3318  res0  4717