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Theorem tfinds2 6955
 Description: Transfinite Induction (inference schema), using implicit substitutions. The first three hypotheses establish the substitutions we need. The last three are the basis and the induction hypotheses (for successor and limit ordinals respectively). Theorem Schema 4 of [Suppes] p. 197. The wff 𝜏 is an auxiliary antecedent to help shorten proofs using this theorem. (Contributed by NM, 4-Sep-2004.)
Hypotheses
Ref Expression
tfinds2.1 (𝑥 = ∅ → (𝜑𝜓))
tfinds2.2 (𝑥 = 𝑦 → (𝜑𝜒))
tfinds2.3 (𝑥 = suc 𝑦 → (𝜑𝜃))
tfinds2.4 (𝜏𝜓)
tfinds2.5 (𝑦 ∈ On → (𝜏 → (𝜒𝜃)))
tfinds2.6 (Lim 𝑥 → (𝜏 → (∀𝑦𝑥 𝜒𝜑)))
Assertion
Ref Expression
tfinds2 (𝑥 ∈ On → (𝜏𝜑))
Distinct variable groups:   𝑥,𝑦,𝜏   𝜓,𝑥   𝜒,𝑥   𝜃,𝑥   𝜑,𝑦
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑦)   𝜒(𝑦)   𝜃(𝑦)

Proof of Theorem tfinds2
StepHypRef Expression
1 tfinds2.4 . . 3 (𝜏𝜓)
2 0ex 4718 . . . 4 ∅ ∈ V
3 tfinds2.1 . . . . 5 (𝑥 = ∅ → (𝜑𝜓))
43imbi2d 329 . . . 4 (𝑥 = ∅ → ((𝜏𝜑) ↔ (𝜏𝜓)))
52, 4sbcie 3437 . . 3 ([∅ / 𝑥](𝜏𝜑) ↔ (𝜏𝜓))
61, 5mpbir 220 . 2 [∅ / 𝑥](𝜏𝜑)
7 vex 3176 . . . . . 6 𝑥 ∈ V
8 tfinds2.5 . . . . . . . 8 (𝑦 ∈ On → (𝜏 → (𝜒𝜃)))
98a2d 29 . . . . . . 7 (𝑦 ∈ On → ((𝜏𝜒) → (𝜏𝜃)))
109sbcth 3417 . . . . . 6 (𝑥 ∈ V → [𝑥 / 𝑦](𝑦 ∈ On → ((𝜏𝜒) → (𝜏𝜃))))
117, 10ax-mp 5 . . . . 5 [𝑥 / 𝑦](𝑦 ∈ On → ((𝜏𝜒) → (𝜏𝜃)))
12 sbcimg 3444 . . . . . 6 (𝑥 ∈ V → ([𝑥 / 𝑦](𝑦 ∈ On → ((𝜏𝜒) → (𝜏𝜃))) ↔ ([𝑥 / 𝑦]𝑦 ∈ On → [𝑥 / 𝑦]((𝜏𝜒) → (𝜏𝜃)))))
137, 12ax-mp 5 . . . . 5 ([𝑥 / 𝑦](𝑦 ∈ On → ((𝜏𝜒) → (𝜏𝜃))) ↔ ([𝑥 / 𝑦]𝑦 ∈ On → [𝑥 / 𝑦]((𝜏𝜒) → (𝜏𝜃))))
1411, 13mpbi 219 . . . 4 ([𝑥 / 𝑦]𝑦 ∈ On → [𝑥 / 𝑦]((𝜏𝜒) → (𝜏𝜃)))
15 sbcel1v 3462 . . . 4 ([𝑥 / 𝑦]𝑦 ∈ On ↔ 𝑥 ∈ On)
16 sbcimg 3444 . . . . 5 (𝑥 ∈ V → ([𝑥 / 𝑦]((𝜏𝜒) → (𝜏𝜃)) ↔ ([𝑥 / 𝑦](𝜏𝜒) → [𝑥 / 𝑦](𝜏𝜃))))
177, 16ax-mp 5 . . . 4 ([𝑥 / 𝑦]((𝜏𝜒) → (𝜏𝜃)) ↔ ([𝑥 / 𝑦](𝜏𝜒) → [𝑥 / 𝑦](𝜏𝜃)))
1814, 15, 173imtr3i 279 . . 3 (𝑥 ∈ On → ([𝑥 / 𝑦](𝜏𝜒) → [𝑥 / 𝑦](𝜏𝜃)))
19 tfinds2.2 . . . . . . 7 (𝑥 = 𝑦 → (𝜑𝜒))
2019bicomd 212 . . . . . 6 (𝑥 = 𝑦 → (𝜒𝜑))
2120equcoms 1934 . . . . 5 (𝑦 = 𝑥 → (𝜒𝜑))
2221imbi2d 329 . . . 4 (𝑦 = 𝑥 → ((𝜏𝜒) ↔ (𝜏𝜑)))
237, 22sbcie 3437 . . 3 ([𝑥 / 𝑦](𝜏𝜒) ↔ (𝜏𝜑))
24 vex 3176 . . . . . . 7 𝑦 ∈ V
2524sucex 6903 . . . . . 6 suc 𝑦 ∈ V
26 tfinds2.3 . . . . . . 7 (𝑥 = suc 𝑦 → (𝜑𝜃))
2726imbi2d 329 . . . . . 6 (𝑥 = suc 𝑦 → ((𝜏𝜑) ↔ (𝜏𝜃)))
2825, 27sbcie 3437 . . . . 5 ([suc 𝑦 / 𝑥](𝜏𝜑) ↔ (𝜏𝜃))
2928sbcbii 3458 . . . 4 ([𝑥 / 𝑦][suc 𝑦 / 𝑥](𝜏𝜑) ↔ [𝑥 / 𝑦](𝜏𝜃))
30 suceq 5707 . . . . 5 (𝑥 = 𝑦 → suc 𝑥 = suc 𝑦)
3130sbcco2 3426 . . . 4 ([𝑥 / 𝑦][suc 𝑦 / 𝑥](𝜏𝜑) ↔ [suc 𝑥 / 𝑥](𝜏𝜑))
3229, 31bitr3i 265 . . 3 ([𝑥 / 𝑦](𝜏𝜃) ↔ [suc 𝑥 / 𝑥](𝜏𝜑))
3318, 23, 323imtr3g 283 . 2 (𝑥 ∈ On → ((𝜏𝜑) → [suc 𝑥 / 𝑥](𝜏𝜑)))
34 sbsbc 3406 . . . 4 ([𝑦 / 𝑥]∀𝑦𝑥 (𝜏𝜒) ↔ [𝑦 / 𝑥]𝑦𝑥 (𝜏𝜒))
3522sbralie 3160 . . . 4 ([𝑦 / 𝑥]∀𝑦𝑥 (𝜏𝜒) ↔ ∀𝑥𝑦 (𝜏𝜑))
3634, 35bitr3i 265 . . 3 ([𝑦 / 𝑥]𝑦𝑥 (𝜏𝜒) ↔ ∀𝑥𝑦 (𝜏𝜑))
37 r19.21v 2943 . . . . . . . 8 (∀𝑦𝑥 (𝜏𝜒) ↔ (𝜏 → ∀𝑦𝑥 𝜒))
38 tfinds2.6 . . . . . . . . 9 (Lim 𝑥 → (𝜏 → (∀𝑦𝑥 𝜒𝜑)))
3938a2d 29 . . . . . . . 8 (Lim 𝑥 → ((𝜏 → ∀𝑦𝑥 𝜒) → (𝜏𝜑)))
4037, 39syl5bi 231 . . . . . . 7 (Lim 𝑥 → (∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)))
4140sbcth 3417 . . . . . 6 (𝑦 ∈ V → [𝑦 / 𝑥](Lim 𝑥 → (∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑))))
4224, 41ax-mp 5 . . . . 5 [𝑦 / 𝑥](Lim 𝑥 → (∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)))
43 sbcimg 3444 . . . . . 6 (𝑦 ∈ V → ([𝑦 / 𝑥](Lim 𝑥 → (∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑))) ↔ ([𝑦 / 𝑥]Lim 𝑥[𝑦 / 𝑥](∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)))))
4424, 43ax-mp 5 . . . . 5 ([𝑦 / 𝑥](Lim 𝑥 → (∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑))) ↔ ([𝑦 / 𝑥]Lim 𝑥[𝑦 / 𝑥](∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑))))
4542, 44mpbi 219 . . . 4 ([𝑦 / 𝑥]Lim 𝑥[𝑦 / 𝑥](∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)))
46 limeq 5652 . . . . 5 (𝑥 = 𝑦 → (Lim 𝑥 ↔ Lim 𝑦))
4724, 46sbcie 3437 . . . 4 ([𝑦 / 𝑥]Lim 𝑥 ↔ Lim 𝑦)
48 sbcimg 3444 . . . . 5 (𝑦 ∈ V → ([𝑦 / 𝑥](∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)) ↔ ([𝑦 / 𝑥]𝑦𝑥 (𝜏𝜒) → [𝑦 / 𝑥](𝜏𝜑))))
4924, 48ax-mp 5 . . . 4 ([𝑦 / 𝑥](∀𝑦𝑥 (𝜏𝜒) → (𝜏𝜑)) ↔ ([𝑦 / 𝑥]𝑦𝑥 (𝜏𝜒) → [𝑦 / 𝑥](𝜏𝜑)))
5045, 47, 493imtr3i 279 . . 3 (Lim 𝑦 → ([𝑦 / 𝑥]𝑦𝑥 (𝜏𝜒) → [𝑦 / 𝑥](𝜏𝜑)))
5136, 50syl5bir 232 . 2 (Lim 𝑦 → (∀𝑥𝑦 (𝜏𝜑) → [𝑦 / 𝑥](𝜏𝜑)))
526, 33, 51tfindes 6954 1 (𝑥 ∈ On → (𝜏𝜑))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 195   = wceq 1475  [wsb 1867   ∈ wcel 1977  ∀wral 2896  Vcvv 3173  [wsbc 3402  ∅c0 3874  Oncon0 5640  Lim wlim 5641  suc csuc 5642 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pr 4833  ax-un 6847 This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-ral 2901  df-rex 2902  df-rab 2905  df-v 3175  df-sbc 3403  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-pss 3556  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-tp 4130  df-op 4132  df-uni 4373  df-br 4584  df-opab 4644  df-tr 4681  df-eprel 4949  df-po 4959  df-so 4960  df-fr 4997  df-we 4999  df-ord 5643  df-on 5644  df-lim 5645  df-suc 5646 This theorem is referenced by:  inar1  9476  grur1a  9520
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