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Theorem setindel 4590
Description: -Induction in terms of membership in a class. (Contributed by Mario Carneiro and Jim Kingdon, 22-Oct-2018.)
Assertion
Ref Expression
setindel (∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆) → 𝑆 = V)
Distinct variable group:   𝑥,𝑦,𝑆

Proof of Theorem setindel
StepHypRef Expression
1 clelsb1 2311 . . . . . . 7 ([𝑦 / 𝑥]𝑥𝑆𝑦𝑆)
21ralbii 2513 . . . . . 6 (∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆 ↔ ∀𝑦𝑥 𝑦𝑆)
3 df-ral 2490 . . . . . 6 (∀𝑦𝑥 𝑦𝑆 ↔ ∀𝑦(𝑦𝑥𝑦𝑆))
42, 3bitri 184 . . . . 5 (∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆 ↔ ∀𝑦(𝑦𝑥𝑦𝑆))
54imbi1i 238 . . . 4 ((∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆𝑥𝑆) ↔ (∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆))
65albii 1494 . . 3 (∀𝑥(∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆𝑥𝑆) ↔ ∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆))
7 ax-setind 4589 . . 3 (∀𝑥(∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆𝑥𝑆) → ∀𝑥 𝑥𝑆)
86, 7sylbir 135 . 2 (∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆) → ∀𝑥 𝑥𝑆)
9 eqv 3481 . 2 (𝑆 = V ↔ ∀𝑥 𝑥𝑆)
108, 9sylibr 134 1 (∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆) → 𝑆 = V)
Colors of variables: wff set class
Syntax hints:  wi 4  wal 1371   = wceq 1373  [wsb 1786  wcel 2177  wral 2485  Vcvv 2773
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2188  ax-setind 4589
This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-ral 2490  df-v 2775
This theorem is referenced by:  setind  4591
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