Theorem inn0 4323

Description: A nonempty intersection. (Contributed by Glauco Siliprandi, 24-Dec-2020.)

Assertion

Ref	Expression
inn0	⊢ ((𝐴 ∩ 𝐵) ≠ ∅ ↔ ∃𝑥 ∈ 𝐴 𝑥 ∈ 𝐵)

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵

Proof of Theorem inn0

Step	Hyp	Ref	Expression
1		nfcv 2924	. 2 ⊢ Ⅎ𝑥𝐴
2		nfcv 2924	. 2 ⊢ Ⅎ𝑥𝐵
3	1, 2	inn0f 4322	1 ⊢ ((𝐴 ∩ 𝐵) ≠ ∅ ↔ ∃𝑥 ∈ 𝐴 𝑥 ∈ 𝐵)

This proof depends on syntax axioms:   ↔ wb 209   ∈ wcel 2145   ≠ wne 2957  ∃wrex 3088   ∩ cin 3901  ∅c0 4282

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-11 2194  ax-12 2215  ax-ext 2734

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ne 2958  df-rex 3089  df-v 3455  df-dif 3905  df-in 3909  df-nul 4283

This theorem is used by:  tgaaddcpbl2  29240  ufdprmidl  33959  sswfaxreg  45818  qinioo  46373