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Theorem setrec1lem3 46395
Description: Lemma for setrec1 46397. If each element 𝑎 of 𝐴 is covered by a set 𝑥 recursively generated by 𝐹, then there is a single such set covering all of 𝐴. The set is constructed explicitly using setrec1lem2 46394. It turns out that 𝑥 = 𝐴 also works, i.e., given the hypotheses it is possible to prove that 𝐴𝑌. I don't know if proving this fact directly using setrec1lem1 46393 would be any easier than the current proof using setrec1lem2 46394, and it would only slightly simplify the proof of setrec1 46397. Other than the use of bnd2d 46387, this is a purely technical theorem for rearranging notation from that of setrec1lem2 46394 to that of setrec1 46397. (Contributed by Emmett Weisz, 20-Jan-2021.) (New usage is discouraged.)
Hypotheses
Ref Expression
setrec1lem3.1 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤𝑦 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑦𝑧)}
setrec1lem3.2 (𝜑𝐴 ∈ V)
setrec1lem3.3 (𝜑 → ∀𝑎𝐴𝑥(𝑎𝑥𝑥𝑌))
Assertion
Ref Expression
setrec1lem3 (𝜑 → ∃𝑥(𝐴𝑥𝑥𝑌))
Distinct variable groups:   𝑦,𝑤,𝑧   𝑥,𝑎,𝐴   𝑌,𝑎,𝑥   𝑥,𝑦,𝐹
Allowed substitution hints:   𝜑(𝑥,𝑦,𝑧,𝑤,𝑎)   𝐴(𝑦,𝑧,𝑤)   𝐹(𝑧,𝑤,𝑎)   𝑌(𝑦,𝑧,𝑤)

Proof of Theorem setrec1lem3
Dummy variable 𝑣 is distinct from all other variables.
StepHypRef Expression
1 setrec1lem3.2 . . . 4 (𝜑𝐴 ∈ V)
2 setrec1lem3.3 . . . . . 6 (𝜑 → ∀𝑎𝐴𝑥(𝑎𝑥𝑥𝑌))
3 exancom 1864 . . . . . . 7 (∃𝑥(𝑎𝑥𝑥𝑌) ↔ ∃𝑥(𝑥𝑌𝑎𝑥))
43ralbii 3092 . . . . . 6 (∀𝑎𝐴𝑥(𝑎𝑥𝑥𝑌) ↔ ∀𝑎𝐴𝑥(𝑥𝑌𝑎𝑥))
52, 4sylib 217 . . . . 5 (𝜑 → ∀𝑎𝐴𝑥(𝑥𝑌𝑎𝑥))
6 df-rex 3070 . . . . . 6 (∃𝑥𝑌 𝑎𝑥 ↔ ∃𝑥(𝑥𝑌𝑎𝑥))
76ralbii 3092 . . . . 5 (∀𝑎𝐴𝑥𝑌 𝑎𝑥 ↔ ∀𝑎𝐴𝑥(𝑥𝑌𝑎𝑥))
85, 7sylibr 233 . . . 4 (𝜑 → ∀𝑎𝐴𝑥𝑌 𝑎𝑥)
91, 8bnd2d 46387 . . 3 (𝜑 → ∃𝑣(𝑣𝑌 ∧ ∀𝑎𝐴𝑥𝑣 𝑎𝑥))
10 exancom 1864 . . . . . . . 8 (∃𝑥(𝑥𝑣𝑎𝑥) ↔ ∃𝑥(𝑎𝑥𝑥𝑣))
11 df-rex 3070 . . . . . . . 8 (∃𝑥𝑣 𝑎𝑥 ↔ ∃𝑥(𝑥𝑣𝑎𝑥))
12 eluni 4842 . . . . . . . 8 (𝑎 𝑣 ↔ ∃𝑥(𝑎𝑥𝑥𝑣))
1310, 11, 123bitr4i 303 . . . . . . 7 (∃𝑥𝑣 𝑎𝑥𝑎 𝑣)
1413ralbii 3092 . . . . . 6 (∀𝑎𝐴𝑥𝑣 𝑎𝑥 ↔ ∀𝑎𝐴 𝑎 𝑣)
15 dfss3 3909 . . . . . 6 (𝐴 𝑣 ↔ ∀𝑎𝐴 𝑎 𝑣)
1614, 15bitr4i 277 . . . . 5 (∀𝑎𝐴𝑥𝑣 𝑎𝑥𝐴 𝑣)
1716anbi2i 623 . . . 4 ((𝑣𝑌 ∧ ∀𝑎𝐴𝑥𝑣 𝑎𝑥) ↔ (𝑣𝑌𝐴 𝑣))
1817exbii 1850 . . 3 (∃𝑣(𝑣𝑌 ∧ ∀𝑎𝐴𝑥𝑣 𝑎𝑥) ↔ ∃𝑣(𝑣𝑌𝐴 𝑣))
199, 18sylib 217 . 2 (𝜑 → ∃𝑣(𝑣𝑌𝐴 𝑣))
20 setrec1lem3.1 . . . . . . 7 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤𝑦 → (𝑤𝑧 → (𝐹𝑤) ⊆ 𝑧)) → 𝑦𝑧)}
21 vex 3436 . . . . . . . 8 𝑣 ∈ V
2221a1i 11 . . . . . . 7 (𝑣𝑌𝑣 ∈ V)
23 id 22 . . . . . . 7 (𝑣𝑌𝑣𝑌)
2420, 22, 23setrec1lem2 46394 . . . . . 6 (𝑣𝑌 𝑣𝑌)
2524anim1i 615 . . . . 5 ((𝑣𝑌𝐴 𝑣) → ( 𝑣𝑌𝐴 𝑣))
2625ancomd 462 . . . 4 ((𝑣𝑌𝐴 𝑣) → (𝐴 𝑣 𝑣𝑌))
2721uniex 7594 . . . . 5 𝑣 ∈ V
28 sseq2 3947 . . . . . 6 (𝑥 = 𝑣 → (𝐴𝑥𝐴 𝑣))
29 eleq1 2826 . . . . . 6 (𝑥 = 𝑣 → (𝑥𝑌 𝑣𝑌))
3028, 29anbi12d 631 . . . . 5 (𝑥 = 𝑣 → ((𝐴𝑥𝑥𝑌) ↔ (𝐴 𝑣 𝑣𝑌)))
3127, 30spcev 3545 . . . 4 ((𝐴 𝑣 𝑣𝑌) → ∃𝑥(𝐴𝑥𝑥𝑌))
3226, 31syl 17 . . 3 ((𝑣𝑌𝐴 𝑣) → ∃𝑥(𝐴𝑥𝑥𝑌))
3332exlimiv 1933 . 2 (∃𝑣(𝑣𝑌𝐴 𝑣) → ∃𝑥(𝐴𝑥𝑥𝑌))
3419, 33syl 17 1 (𝜑 → ∃𝑥(𝐴𝑥𝑥𝑌))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 396  wal 1537   = wceq 1539  wex 1782  wcel 2106  {cab 2715  wral 3064  wrex 3065  Vcvv 3432  wss 3887   cuni 4839  cfv 6433
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2709  ax-rep 5209  ax-sep 5223  ax-nul 5230  ax-pow 5288  ax-pr 5352  ax-un 7588  ax-reg 9351  ax-inf2 9399
This theorem depends on definitions:  df-bi 206  df-an 397  df-or 845  df-3or 1087  df-3an 1088  df-tru 1542  df-fal 1552  df-ex 1783  df-nf 1787  df-sb 2068  df-mo 2540  df-eu 2569  df-clab 2716  df-cleq 2730  df-clel 2816  df-nfc 2889  df-ne 2944  df-ral 3069  df-rex 3070  df-reu 3072  df-rab 3073  df-v 3434  df-sbc 3717  df-csb 3833  df-dif 3890  df-un 3892  df-in 3894  df-ss 3904  df-pss 3906  df-nul 4257  df-if 4460  df-pw 4535  df-sn 4562  df-pr 4564  df-op 4568  df-uni 4840  df-int 4880  df-iun 4926  df-iin 4927  df-br 5075  df-opab 5137  df-mpt 5158  df-tr 5192  df-id 5489  df-eprel 5495  df-po 5503  df-so 5504  df-fr 5544  df-we 5546  df-xp 5595  df-rel 5596  df-cnv 5597  df-co 5598  df-dm 5599  df-rn 5600  df-res 5601  df-ima 5602  df-pred 6202  df-ord 6269  df-on 6270  df-lim 6271  df-suc 6272  df-iota 6391  df-fun 6435  df-fn 6436  df-f 6437  df-f1 6438  df-fo 6439  df-f1o 6440  df-fv 6441  df-ov 7278  df-om 7713  df-2nd 7832  df-frecs 8097  df-wrecs 8128  df-recs 8202  df-rdg 8241  df-r1 9522  df-rank 9523
This theorem is referenced by:  setrec1  46397
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