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Theorem tfis2f 4307
 Description: Transfinite Induction Schema, using implicit substitution. (Contributed by NM, 18-Aug-1994.)
Hypotheses
Ref Expression
tfis2f.1 𝑥𝜓
tfis2f.2 (𝑥 = 𝑦 → (𝜑𝜓))
tfis2f.3 (𝑥 ∈ On → (∀𝑦𝑥 𝜓𝜑))
Assertion
Ref Expression
tfis2f (𝑥 ∈ On → 𝜑)
Distinct variable groups:   𝜑,𝑦   𝑥,𝑦
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑥,𝑦)

Proof of Theorem tfis2f
StepHypRef Expression
1 tfis2f.1 . . . . 5 𝑥𝜓
2 tfis2f.2 . . . . 5 (𝑥 = 𝑦 → (𝜑𝜓))
31, 2sbie 1674 . . . 4 ([𝑦 / 𝑥]𝜑𝜓)
43ralbii 2330 . . 3 (∀𝑦𝑥 [𝑦 / 𝑥]𝜑 ↔ ∀𝑦𝑥 𝜓)
5 tfis2f.3 . . 3 (𝑥 ∈ On → (∀𝑦𝑥 𝜓𝜑))
64, 5syl5bi 141 . 2 (𝑥 ∈ On → (∀𝑦𝑥 [𝑦 / 𝑥]𝜑𝜑))
76tfis 4306 1 (𝑥 ∈ On → 𝜑)
 Colors of variables: wff set class Syntax hints:   → wi 4   ↔ wb 98  Ⅎwnf 1349   ∈ wcel 1393  [wsb 1645  ∀wral 2306  Oncon0 4100 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022  ax-setind 4262 This theorem depends on definitions:  df-bi 110  df-3an 887  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-ral 2311  df-rex 2312  df-rab 2315  df-v 2559  df-in 2924  df-ss 2931  df-uni 3581  df-tr 3855  df-iord 4103  df-on 4105 This theorem is referenced by:  tfis2  4308  tfri3  5953
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