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Theorem setrec1lem4 49851
Description: Lemma for setrec1 49852. If 𝑋 is recursively generated by 𝐹, then so is 𝑋 ∪ (𝐹𝐴).

In the proof of setrec1 49852, the following is substituted for this theorem's 𝜑: (𝜑 ∧ (𝐴𝑥𝑥 ∈ {𝑦 ∣ ∀𝑧(∀𝑤 (𝑤𝑦 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑦𝑧)})) Therefore, we cannot declare 𝑧 to be a distinct variable from 𝜑, since we need it to appear as a bound variable in 𝜑. This theorem can be proven without the hypothesis 𝑧𝜑, but the proof would be harder to read because theorems in deduction form would be interrupted by theorems like eximi 1836, making the antecedent of each line something more complicated than 𝜑. The proof of setrec1lem2 49849 could similarly be made easier to read by adding the hypothesis 𝑧𝜑, but I had already finished the proof and decided to leave it as is. (Contributed by Emmett Weisz, 26-Nov-2020.) (New usage is discouraged.)

Hypotheses
Ref Expression
setrec1lem4.1 𝑧𝜑
setrec1lem4.2 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤𝑦 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑦𝑧)}
setrec1lem4.3 (𝜑𝐴 ∈ V)
setrec1lem4.4 (𝜑𝐴𝑋)
setrec1lem4.5 (𝜑𝑋𝑌)
Assertion
Ref Expression
setrec1lem4 (𝜑 → (𝑋 ∪ (𝐹𝐴)) ∈ 𝑌)
Distinct variable groups:   𝑦,𝑤,𝑧,𝐴   𝑤,𝐹,𝑦,𝑧   𝑤,𝑋,𝑦,𝑧
Allowed substitution hints:   𝜑(𝑦,𝑧,𝑤)   𝑌(𝑦,𝑧,𝑤)

Proof of Theorem setrec1lem4
StepHypRef Expression
1 setrec1lem4.1 . . 3 𝑧𝜑
2 id 22 . . . . . . . 8 (𝑤𝑋𝑤𝑋)
3 ssun1 4127 . . . . . . . 8 𝑋 ⊆ (𝑋 ∪ (𝐹𝐴))
42, 3sstrdi 3943 . . . . . . 7 (𝑤𝑋𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)))
54imim1i 63 . . . . . 6 ((𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)))
65alimi 1812 . . . . 5 (∀𝑤(𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → ∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)))
7 setrec1lem4.5 . . . . . . . 8 (𝜑𝑋𝑌)
8 setrec1lem4.2 . . . . . . . . 9 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤𝑦 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑦𝑧)}
98, 7setrec1lem1 49848 . . . . . . . 8 (𝜑 → (𝑋𝑌 ↔ ∀𝑧(∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑋𝑧)))
107, 9mpbid 232 . . . . . . 7 (𝜑 → ∀𝑧(∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑋𝑧))
11 sp 2188 . . . . . . 7 (∀𝑧(∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑋𝑧) → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑋𝑧))
1210, 11syl 17 . . . . . 6 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑋𝑧))
13 setrec1lem4.4 . . . . . . . . 9 (𝜑𝐴𝑋)
14 sstr2 3937 . . . . . . . . 9 (𝐴𝑋 → (𝑋𝑧𝐴𝑧))
1513, 14syl 17 . . . . . . . 8 (𝜑 → (𝑋𝑧𝐴𝑧))
1612, 15syld 47 . . . . . . 7 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝐴𝑧))
17 setrec1lem4.3 . . . . . . . . 9 (𝜑𝐴 ∈ V)
18 sseq1 3956 . . . . . . . . . 10 (𝑤 = 𝐴 → (𝑤𝑋𝐴𝑋))
19 sseq1 3956 . . . . . . . . . . 11 (𝑤 = 𝐴 → (𝑤𝑧𝐴𝑧))
20 fveq2 6831 . . . . . . . . . . . 12 (𝑤 = 𝐴 → (𝐹𝑤) = (𝐹𝐴))
2120sseq1d 3962 . . . . . . . . . . 11 (𝑤 = 𝐴 → ((𝐹𝑤) ⊆ 𝑧 ↔ (𝐹𝐴) ⊆ 𝑧))
2219, 21imbi12d 344 . . . . . . . . . 10 (𝑤 = 𝐴 → ((𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧) ↔ (𝐴𝑧 → (𝐹𝐴) ⊆ 𝑧)))
2318, 22imbi12d 344 . . . . . . . . 9 (𝑤 = 𝐴 → ((𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) ↔ (𝐴𝑋 → (𝐴𝑧 → (𝐹𝐴) ⊆ 𝑧))))
2417, 23spcdvw 49840 . . . . . . . 8 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝐴𝑋 → (𝐴𝑧 → (𝐹𝐴) ⊆ 𝑧))))
2513, 24mpid 44 . . . . . . 7 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝐴𝑧 → (𝐹𝐴) ⊆ 𝑧)))
2616, 25mpdd 43 . . . . . 6 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝐹𝐴) ⊆ 𝑧))
2712, 26jcad 512 . . . . 5 (𝜑 → (∀𝑤(𝑤𝑋 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑋𝑧 ∧ (𝐹𝐴) ⊆ 𝑧)))
286, 27syl5 34 . . . 4 (𝜑 → (∀𝑤(𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑋𝑧 ∧ (𝐹𝐴) ⊆ 𝑧)))
29 unss 4139 . . . 4 ((𝑋𝑧 ∧ (𝐹𝐴) ⊆ 𝑧) ↔ (𝑋 ∪ (𝐹𝐴)) ⊆ 𝑧)
3028, 29imbitrdi 251 . . 3 (𝜑 → (∀𝑤(𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑋 ∪ (𝐹𝐴)) ⊆ 𝑧))
311, 30alrimi 2218 . 2 (𝜑 → ∀𝑧(∀𝑤(𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑋 ∪ (𝐹𝐴)) ⊆ 𝑧))
32 fvex 6844 . . . 4 (𝐹𝐴) ∈ V
33 unexg 7685 . . . 4 ((𝑋𝑌 ∧ (𝐹𝐴) ∈ V) → (𝑋 ∪ (𝐹𝐴)) ∈ V)
347, 32, 33sylancl 586 . . 3 (𝜑 → (𝑋 ∪ (𝐹𝐴)) ∈ V)
358, 34setrec1lem1 49848 . 2 (𝜑 → ((𝑋 ∪ (𝐹𝐴)) ∈ 𝑌 ↔ ∀𝑧(∀𝑤(𝑤 ⊆ (𝑋 ∪ (𝐹𝐴)) → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → (𝑋 ∪ (𝐹𝐴)) ⊆ 𝑧)))
3631, 35mpbird 257 1 (𝜑 → (𝑋 ∪ (𝐹𝐴)) ∈ 𝑌)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 395  wal 1539   = wceq 1541  wnf 1784  wcel 2113  {cab 2711  Vcvv 3437  cun 3896  wss 3898  cfv 6489
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2182  ax-ext 2705  ax-sep 5238  ax-nul 5248  ax-pr 5374  ax-un 7677
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-clab 2712  df-cleq 2725  df-clel 2808  df-nfc 2882  df-ne 2930  df-rab 3397  df-v 3439  df-dif 3901  df-un 3903  df-ss 3915  df-nul 4283  df-if 4477  df-sn 4578  df-pr 4580  df-op 4584  df-uni 4861  df-br 5096  df-iota 6445  df-fv 6497
This theorem is referenced by:  setrec1  49852
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