Theorem setrec1lem3 50345

Description: Lemma for setrec1 50347. 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 50344. It turns out that 𝑥 = 𝐴 also works, i.e., given the hypotheses it is possible to prove that 𝐴 ∈ 𝑌. I don't know if proving this fact directly using setrec1lem1 50343 would be any easier than the current proof using setrec1lem2 50344, and it would only slightly simplify the proof of setrec1 50347. Other than the use of bnd2d 50337, this is a purely technical theorem for rearranging notation from that of setrec1lem2 50344 to that of setrec1 50347. (Contributed by Emmett Weisz, 20-Jan-2021.) (New usage is discouraged.)

Hypotheses

Ref	Expression
setrec1lem3.1	⊢ 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤 ⊆ 𝑦 → (𝑤 ⊆ 𝑧 → (𝐹‘𝑤) ⊆ 𝑧)) → 𝑦 ⊆ 𝑧)}
setrec1lem3.2	⊢ (𝜑 → 𝐴 ∈ V)
setrec1lem3.3	⊢ (𝜑 → ∀𝑎 ∈ 𝐴 ∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑌))

Assertion

Ref	Expression
setrec1lem3	⊢ (𝜑 → ∃𝑥(𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌))

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.

Step	Hyp	Ref	Expression
1		setrec1lem3.2	. . . 4 ⊢ (𝜑 → 𝐴 ∈ V)
2		setrec1lem3.3	. . . . . 6 ⊢ (𝜑 → ∀𝑎 ∈ 𝐴 ∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑌))
3		exancom 1888	. . . . . . 7 ⊢ (∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑌) ↔ ∃𝑥(𝑥 ∈ 𝑌 ∧ 𝑎 ∈ 𝑥))
4	3	ralbii 3117	. . . . . 6 ⊢ (∀𝑎 ∈ 𝐴 ∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑌) ↔ ∀𝑎 ∈ 𝐴 ∃𝑥(𝑥 ∈ 𝑌 ∧ 𝑎 ∈ 𝑥))
5	2, 4	sylib 221	. . . . 5 ⊢ (𝜑 → ∀𝑎 ∈ 𝐴 ∃𝑥(𝑥 ∈ 𝑌 ∧ 𝑎 ∈ 𝑥))
6		df-rex 3096	. . . . . 6 ⊢ (∃𝑥 ∈ 𝑌 𝑎 ∈ 𝑥 ↔ ∃𝑥(𝑥 ∈ 𝑌 ∧ 𝑎 ∈ 𝑥))
7	6	ralbii 3117	. . . . 5 ⊢ (∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑌 𝑎 ∈ 𝑥 ↔ ∀𝑎 ∈ 𝐴 ∃𝑥(𝑥 ∈ 𝑌 ∧ 𝑎 ∈ 𝑥))
8	5, 7	sylibr 237	. . . 4 ⊢ (𝜑 → ∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑌 𝑎 ∈ 𝑥)
9	1, 8	bnd2d 50337	. . 3 ⊢ (𝜑 → ∃𝑣(𝑣 ⊆ 𝑌 ∧ ∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥))
10		exancom 1888	. . . . . . . 8 ⊢ (∃𝑥(𝑥 ∈ 𝑣 ∧ 𝑎 ∈ 𝑥) ↔ ∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑣))
11		df-rex 3096	. . . . . . . 8 ⊢ (∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝑎 ∈ 𝑥))
12		eluni 4876	. . . . . . . 8 ⊢ (𝑎 ∈ ∪ 𝑣 ↔ ∃𝑥(𝑎 ∈ 𝑥 ∧ 𝑥 ∈ 𝑣))
13	10, 11, 12	3bitr4i 306	. . . . . . 7 ⊢ (∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥 ↔ 𝑎 ∈ ∪ 𝑣)
14	13	ralbii 3117	. . . . . 6 ⊢ (∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥 ↔ ∀𝑎 ∈ 𝐴 𝑎 ∈ ∪ 𝑣)
15		dfss3 3934	. . . . . 6 ⊢ (𝐴 ⊆ ∪ 𝑣 ↔ ∀𝑎 ∈ 𝐴 𝑎 ∈ ∪ 𝑣)
16	14, 15	bitr4i 281	. . . . 5 ⊢ (∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥 ↔ 𝐴 ⊆ ∪ 𝑣)
17	16	anbi2i 634	. . . 4 ⊢ ((𝑣 ⊆ 𝑌 ∧ ∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥) ↔ (𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣))
18	17	exbii 1875	. . 3 ⊢ (∃𝑣(𝑣 ⊆ 𝑌 ∧ ∀𝑎 ∈ 𝐴 ∃𝑥 ∈ 𝑣 𝑎 ∈ 𝑥) ↔ ∃𝑣(𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣))
19	9, 18	sylib 221	. 2 ⊢ (𝜑 → ∃𝑣(𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣))
20		setrec1lem3.1	. . . . . . 7 ⊢ 𝑌 = {𝑦 ∣ ∀𝑧(∀𝑤(𝑤 ⊆ 𝑦 → (𝑤 ⊆ 𝑧 → (𝐹‘𝑤) ⊆ 𝑧)) → 𝑦 ⊆ 𝑧)}
21		vex 3467	. . . . . . . 8 ⊢ 𝑣 ∈ V
22	21	a1i 11	. . . . . . 7 ⊢ (𝑣 ⊆ 𝑌 → 𝑣 ∈ V)
23		id 23	. . . . . . 7 ⊢ (𝑣 ⊆ 𝑌 → 𝑣 ⊆ 𝑌)
24	20, 22, 23	setrec1lem2 50344	. . . . . 6 ⊢ (𝑣 ⊆ 𝑌 → ∪ 𝑣 ∈ 𝑌)
25	24	anim1i 626	. . . . 5 ⊢ ((𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣) → (∪ 𝑣 ∈ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣))
26	25	ancomd 466	. . . 4 ⊢ ((𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣) → (𝐴 ⊆ ∪ 𝑣 ∧ ∪ 𝑣 ∈ 𝑌))
27	21	uniex 7736	. . . . 5 ⊢ ∪ 𝑣 ∈ V
28		sseq2 3971	. . . . . 6 ⊢ (𝑥 = ∪ 𝑣 → (𝐴 ⊆ 𝑥 ↔ 𝐴 ⊆ ∪ 𝑣))
29		eleq1 2857	. . . . . 6 ⊢ (𝑥 = ∪ 𝑣 → (𝑥 ∈ 𝑌 ↔ ∪ 𝑣 ∈ 𝑌))
30	28, 29	anbi12d 643	. . . . 5 ⊢ (𝑥 = ∪ 𝑣 → ((𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌) ↔ (𝐴 ⊆ ∪ 𝑣 ∧ ∪ 𝑣 ∈ 𝑌)))
31	27, 30	spcev 3574	. . . 4 ⊢ ((𝐴 ⊆ ∪ 𝑣 ∧ ∪ 𝑣 ∈ 𝑌) → ∃𝑥(𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌))
32	26, 31	syl 18	. . 3 ⊢ ((𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣) → ∃𝑥(𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌))
33	32	exlimiv 1957	. 2 ⊢ (∃𝑣(𝑣 ⊆ 𝑌 ∧ 𝐴 ⊆ ∪ 𝑣) → ∃𝑥(𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌))
34	19, 33	syl 18	1 ⊢ (𝜑 → ∃𝑥(𝐴 ⊆ 𝑥 ∧ 𝑥 ∈ 𝑌))

Syntax hints:   → wi 4   ∧ wa 400  ∀wal 1565   = wceq 1567  ∃wex 1806   ∈ wcel 2149  {cab 2747  ∀wral 3085  ∃wrex 3095  Vcvv 3463   ⊆ wss 3913  ∪ cuni 4873  ‘cfv 6533

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836  ax-5 1937  ax-6 1994  ax-7 2035  ax-8 2151  ax-9 2159  ax-10 2182  ax-11 2198  ax-12 2219  ax-ext 2741  ax-rep 5239  ax-sep 5258  ax-nul 5268  ax-pow 5334  ax-pr 5402  ax-un 7730  ax-reg 9550  ax-inf2 9606

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3or 1102  df-3an 1103  df-tru 1570  df-fal 1580  df-ex 1807  df-nf 1811  df-sb 2098  df-mo 2573  df-eu 2603  df-clab 2748  df-cleq 2761  df-clel 2844  df-nfc 2918  df-ne 2965  df-ral 3086  df-rex 3096  df-reu 3377  df-rab 3424  df-v 3465  df-sbc 3754  df-csb 3862  df-dif 3916  df-un 3918  df-in 3920  df-ss 3930  df-pss 3933  df-nul 4295  df-if 4490  df-pw 4566  df-sn 4592  df-pr 4594  df-op 4598  df-uni 4874  df-int 4914  df-iun 4959  df-iin 4960  df-br 5111  df-opab 5175  df-mpt 5194  df-tr 5220  df-id 5554  df-eprel 5559  df-po 5567  df-so 5568  df-fr 5612  df-we 5614  df-xp 5665  df-rel 5666  df-cnv 5667  df-co 5668  df-dm 5669  df-rn 5670  df-res 5671  df-ima 5672  df-pred 6299  df-ord 6360  df-on 6361  df-lim 6362  df-suc 6363  df-iota 6489  df-fun 6535  df-fn 6536  df-f 6537  df-f1 6538  df-fo 6539  df-f1o 6540  df-fv 6541  df-ov 7411  df-om 7859  df-2nd 7983  df-frecs 8274  df-wrecs 8305  df-recs 8354  df-rdg 8393  df-r1 9732  df-rank 9733

This theorem is referenced by:  setrec1  50347