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Theorem wfrlem10 7469
Description: Lemma for well-founded recursion. When 𝑧 is an 𝑅 minimal element of (𝐴 ∖ dom 𝐹), then its predecessor class is equal to dom 𝐹. (Contributed by Scott Fenton, 21-Apr-2011.)
Hypotheses
Ref Expression
wfrlem10.1 𝑅 We 𝐴
wfrlem10.2 𝐹 = wrecs(𝑅, 𝐴, 𝐺)
Assertion
Ref Expression
wfrlem10 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ Pred(𝑅, (𝐴 ∖ dom 𝐹), 𝑧) = ∅) → Pred(𝑅, 𝐴, 𝑧) = dom 𝐹)
Distinct variable group:   𝑧,𝐴
Allowed substitution hints:   𝑅(𝑧)   𝐹(𝑧)   𝐺(𝑧)

Proof of Theorem wfrlem10
Dummy variable 𝑤 is distinct from all other variables.
StepHypRef Expression
1 wfrlem10.2 . . . 4 𝐹 = wrecs(𝑅, 𝐴, 𝐺)
21wfrlem8 7467 . . 3 (Pred(𝑅, (𝐴 ∖ dom 𝐹), 𝑧) = ∅ ↔ Pred(𝑅, 𝐴, 𝑧) = Pred(𝑅, dom 𝐹, 𝑧))
32biimpi 206 . 2 (Pred(𝑅, (𝐴 ∖ dom 𝐹), 𝑧) = ∅ → Pred(𝑅, 𝐴, 𝑧) = Pred(𝑅, dom 𝐹, 𝑧))
4 predss 5725 . . . 4 Pred(𝑅, dom 𝐹, 𝑧) ⊆ dom 𝐹
54a1i 11 . . 3 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → Pred(𝑅, dom 𝐹, 𝑧) ⊆ dom 𝐹)
6 simpr 476 . . . . . 6 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → 𝑤 ∈ dom 𝐹)
7 eldifn 3766 . . . . . . . . . 10 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → ¬ 𝑧 ∈ dom 𝐹)
8 eleq1 2718 . . . . . . . . . . 11 (𝑤 = 𝑧 → (𝑤 ∈ dom 𝐹𝑧 ∈ dom 𝐹))
98notbid 307 . . . . . . . . . 10 (𝑤 = 𝑧 → (¬ 𝑤 ∈ dom 𝐹 ↔ ¬ 𝑧 ∈ dom 𝐹))
107, 9syl5ibrcom 237 . . . . . . . . 9 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → (𝑤 = 𝑧 → ¬ 𝑤 ∈ dom 𝐹))
1110con2d 129 . . . . . . . 8 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → (𝑤 ∈ dom 𝐹 → ¬ 𝑤 = 𝑧))
1211imp 444 . . . . . . 7 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → ¬ 𝑤 = 𝑧)
131wfrdmcl 7468 . . . . . . . . . 10 (𝑤 ∈ dom 𝐹 → Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹)
1413adantl 481 . . . . . . . . 9 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹)
15 ssel 3630 . . . . . . . . . . . 12 (Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹 → (𝑧 ∈ Pred(𝑅, 𝐴, 𝑤) → 𝑧 ∈ dom 𝐹))
1615con3d 148 . . . . . . . . . . 11 (Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹 → (¬ 𝑧 ∈ dom 𝐹 → ¬ 𝑧 ∈ Pred(𝑅, 𝐴, 𝑤)))
177, 16syl5com 31 . . . . . . . . . 10 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → (Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹 → ¬ 𝑧 ∈ Pred(𝑅, 𝐴, 𝑤)))
1817adantr 480 . . . . . . . . 9 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → (Pred(𝑅, 𝐴, 𝑤) ⊆ dom 𝐹 → ¬ 𝑧 ∈ Pred(𝑅, 𝐴, 𝑤)))
1914, 18mpd 15 . . . . . . . 8 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → ¬ 𝑧 ∈ Pred(𝑅, 𝐴, 𝑤))
20 eldifi 3765 . . . . . . . . 9 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → 𝑧𝐴)
21 elpredg 5732 . . . . . . . . . 10 ((𝑤 ∈ dom 𝐹𝑧𝐴) → (𝑧 ∈ Pred(𝑅, 𝐴, 𝑤) ↔ 𝑧𝑅𝑤))
2221ancoms 468 . . . . . . . . 9 ((𝑧𝐴𝑤 ∈ dom 𝐹) → (𝑧 ∈ Pred(𝑅, 𝐴, 𝑤) ↔ 𝑧𝑅𝑤))
2320, 22sylan 487 . . . . . . . 8 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → (𝑧 ∈ Pred(𝑅, 𝐴, 𝑤) ↔ 𝑧𝑅𝑤))
2419, 23mtbid 313 . . . . . . 7 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → ¬ 𝑧𝑅𝑤)
251wfrdmss 7466 . . . . . . . . 9 dom 𝐹𝐴
2625sseli 3632 . . . . . . . 8 (𝑤 ∈ dom 𝐹𝑤𝐴)
27 wfrlem10.1 . . . . . . . . . 10 𝑅 We 𝐴
28 weso 5134 . . . . . . . . . 10 (𝑅 We 𝐴𝑅 Or 𝐴)
2927, 28ax-mp 5 . . . . . . . . 9 𝑅 Or 𝐴
30 solin 5087 . . . . . . . . 9 ((𝑅 Or 𝐴 ∧ (𝑤𝐴𝑧𝐴)) → (𝑤𝑅𝑧𝑤 = 𝑧𝑧𝑅𝑤))
3129, 30mpan 706 . . . . . . . 8 ((𝑤𝐴𝑧𝐴) → (𝑤𝑅𝑧𝑤 = 𝑧𝑧𝑅𝑤))
3226, 20, 31syl2anr 494 . . . . . . 7 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → (𝑤𝑅𝑧𝑤 = 𝑧𝑧𝑅𝑤))
3312, 24, 32ecase23d 1476 . . . . . 6 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → 𝑤𝑅𝑧)
34 vex 3234 . . . . . . 7 𝑧 ∈ V
35 vex 3234 . . . . . . . 8 𝑤 ∈ V
3635elpred 5731 . . . . . . 7 (𝑧 ∈ V → (𝑤 ∈ Pred(𝑅, dom 𝐹, 𝑧) ↔ (𝑤 ∈ dom 𝐹𝑤𝑅𝑧)))
3734, 36ax-mp 5 . . . . . 6 (𝑤 ∈ Pred(𝑅, dom 𝐹, 𝑧) ↔ (𝑤 ∈ dom 𝐹𝑤𝑅𝑧))
386, 33, 37sylanbrc 699 . . . . 5 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ 𝑤 ∈ dom 𝐹) → 𝑤 ∈ Pred(𝑅, dom 𝐹, 𝑧))
3938ex 449 . . . 4 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → (𝑤 ∈ dom 𝐹𝑤 ∈ Pred(𝑅, dom 𝐹, 𝑧)))
4039ssrdv 3642 . . 3 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → dom 𝐹 ⊆ Pred(𝑅, dom 𝐹, 𝑧))
415, 40eqssd 3653 . 2 (𝑧 ∈ (𝐴 ∖ dom 𝐹) → Pred(𝑅, dom 𝐹, 𝑧) = dom 𝐹)
423, 41sylan9eqr 2707 1 ((𝑧 ∈ (𝐴 ∖ dom 𝐹) ∧ Pred(𝑅, (𝐴 ∖ dom 𝐹), 𝑧) = ∅) → Pred(𝑅, 𝐴, 𝑧) = dom 𝐹)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 196  wa 383  w3o 1053   = wceq 1523  wcel 2030  Vcvv 3231  cdif 3604  wss 3607  c0 3948   class class class wbr 4685   Or wor 5063   We wwe 5101  dom cdm 5143  Predcpred 5717  wrecscwrecs 7451
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1762  ax-4 1777  ax-5 1879  ax-6 1945  ax-7 1981  ax-9 2039  ax-10 2059  ax-11 2074  ax-12 2087  ax-13 2282  ax-ext 2631  ax-sep 4814  ax-nul 4822  ax-pr 4936
This theorem depends on definitions:  df-bi 197  df-or 384  df-an 385  df-3or 1055  df-3an 1056  df-tru 1526  df-ex 1745  df-nf 1750  df-sb 1938  df-eu 2502  df-mo 2503  df-clab 2638  df-cleq 2644  df-clel 2647  df-nfc 2782  df-ral 2946  df-rex 2947  df-rab 2950  df-v 3233  df-sbc 3469  df-dif 3610  df-un 3612  df-in 3614  df-ss 3621  df-nul 3949  df-if 4120  df-sn 4211  df-pr 4213  df-op 4217  df-uni 4469  df-iun 4554  df-br 4686  df-opab 4746  df-so 5065  df-we 5104  df-xp 5149  df-rel 5150  df-cnv 5151  df-co 5152  df-dm 5153  df-rn 5154  df-res 5155  df-ima 5156  df-pred 5718  df-iota 5889  df-fun 5928  df-fn 5929  df-fv 5934  df-wrecs 7452
This theorem is referenced by:  wfrlem15  7474
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