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Theorem setindel 4536
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 2282 . . . . . . 7 ([𝑦 / 𝑥]𝑥𝑆𝑦𝑆)
21ralbii 2483 . . . . . 6 (∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆 ↔ ∀𝑦𝑥 𝑦𝑆)
3 df-ral 2460 . . . . . 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 1470 . . 3 (∀𝑥(∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆𝑥𝑆) ↔ ∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆))
7 ax-setind 4535 . . 3 (∀𝑥(∀𝑦𝑥 [𝑦 / 𝑥]𝑥𝑆𝑥𝑆) → ∀𝑥 𝑥𝑆)
86, 7sylbir 135 . 2 (∀𝑥(∀𝑦(𝑦𝑥𝑦𝑆) → 𝑥𝑆) → ∀𝑥 𝑥𝑆)
9 eqv 3442 . 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 1351   = wceq 1353  [wsb 1762  wcel 2148  wral 2455  Vcvv 2737
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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159  ax-setind 4535
This theorem depends on definitions:  df-bi 117  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-ral 2460  df-v 2739
This theorem is referenced by:  setind  4537
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