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Theorem intmin3 3670
 Description: Under subset ordering, the intersection of a class abstraction is less than or equal to any of its members. (Contributed by NM, 3-Jul-2005.)
Hypotheses
Ref Expression
intmin3.2 (𝑥 = 𝐴 → (𝜑𝜓))
intmin3.3 𝜓
Assertion
Ref Expression
intmin3 (𝐴𝑉 {𝑥𝜑} ⊆ 𝐴)
Distinct variable groups:   𝑥,𝐴   𝜓,𝑥
Allowed substitution hints:   𝜑(𝑥)   𝑉(𝑥)

Proof of Theorem intmin3
StepHypRef Expression
1 intmin3.3 . . 3 𝜓
2 intmin3.2 . . . 4 (𝑥 = 𝐴 → (𝜑𝜓))
32elabg 2711 . . 3 (𝐴𝑉 → (𝐴 ∈ {𝑥𝜑} ↔ 𝜓))
41, 3mpbiri 161 . 2 (𝐴𝑉𝐴 ∈ {𝑥𝜑})
5 intss1 3658 . 2 (𝐴 ∈ {𝑥𝜑} → {𝑥𝜑} ⊆ 𝐴)
64, 5syl 14 1 (𝐴𝑉 {𝑥𝜑} ⊆ 𝐴)
 Colors of variables: wff set class Syntax hints:   → wi 4   ↔ wb 102   = wceq 1259   ∈ wcel 1409  {cab 2042   ⊆ wss 2945  ∩ cint 3643 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038 This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-v 2576  df-in 2952  df-ss 2959  df-int 3644 This theorem is referenced by:  intid  3988
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