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Theorem sbthlem7 6980
Description: Lemma for isbth 6984. (Contributed by NM, 27-Mar-1998.)
Hypotheses
Ref Expression
sbthlem.1 𝐴 ∈ V
sbthlem.2 𝐷 = {𝑥 ∣ (𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥))}
sbthlem.3 𝐻 = ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷)))
Assertion
Ref Expression
sbthlem7 ((Fun 𝑓 ∧ Fun 𝑔) → Fun 𝐻)
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐷   𝑥,𝑓   𝑥,𝑔   𝑥,𝐻
Allowed substitution hints:   𝐴(𝑓,𝑔)   𝐵(𝑓,𝑔)   𝐷(𝑓,𝑔)   𝐻(𝑓,𝑔)

Proof of Theorem sbthlem7
StepHypRef Expression
1 funres 5272 . . 3 (Fun 𝑓 → Fun (𝑓 𝐷))
2 funres 5272 . . 3 (Fun 𝑔 → Fun (𝑔 ↾ (𝐴 𝐷)))
3 dmres 4943 . . . . . . . . 9 dom (𝑓 𝐷) = ( 𝐷 ∩ dom 𝑓)
4 inss1 3370 . . . . . . . . 9 ( 𝐷 ∩ dom 𝑓) ⊆ 𝐷
53, 4eqsstri 3202 . . . . . . . 8 dom (𝑓 𝐷) ⊆ 𝐷
6 ssrin 3375 . . . . . . . 8 (dom (𝑓 𝐷) ⊆ 𝐷 → (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ( 𝐷 ∩ dom (𝑔 ↾ (𝐴 𝐷))))
75, 6ax-mp 5 . . . . . . 7 (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ( 𝐷 ∩ dom (𝑔 ↾ (𝐴 𝐷)))
8 dmres 4943 . . . . . . . . 9 dom (𝑔 ↾ (𝐴 𝐷)) = ((𝐴 𝐷) ∩ dom 𝑔)
9 inss1 3370 . . . . . . . . 9 ((𝐴 𝐷) ∩ dom 𝑔) ⊆ (𝐴 𝐷)
108, 9eqsstri 3202 . . . . . . . 8 dom (𝑔 ↾ (𝐴 𝐷)) ⊆ (𝐴 𝐷)
11 sslin 3376 . . . . . . . 8 (dom (𝑔 ↾ (𝐴 𝐷)) ⊆ (𝐴 𝐷) → ( 𝐷 ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ( 𝐷 ∩ (𝐴 𝐷)))
1210, 11ax-mp 5 . . . . . . 7 ( 𝐷 ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ( 𝐷 ∩ (𝐴 𝐷))
137, 12sstri 3179 . . . . . 6 (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ( 𝐷 ∩ (𝐴 𝐷))
14 disjdif 3510 . . . . . 6 ( 𝐷 ∩ (𝐴 𝐷)) = ∅
1513, 14sseqtri 3204 . . . . 5 (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ∅
16 ss0 3478 . . . . 5 ((dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) ⊆ ∅ → (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) = ∅)
1715, 16ax-mp 5 . . . 4 (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) = ∅
18 funun 5275 . . . 4 (((Fun (𝑓 𝐷) ∧ Fun (𝑔 ↾ (𝐴 𝐷))) ∧ (dom (𝑓 𝐷) ∩ dom (𝑔 ↾ (𝐴 𝐷))) = ∅) → Fun ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷))))
1917, 18mpan2 425 . . 3 ((Fun (𝑓 𝐷) ∧ Fun (𝑔 ↾ (𝐴 𝐷))) → Fun ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷))))
201, 2, 19syl2an 289 . 2 ((Fun 𝑓 ∧ Fun 𝑔) → Fun ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷))))
21 sbthlem.3 . . 3 𝐻 = ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷)))
2221funeqi 5252 . 2 (Fun 𝐻 ↔ Fun ((𝑓 𝐷) ∪ (𝑔 ↾ (𝐴 𝐷))))
2320, 22sylibr 134 1 ((Fun 𝑓 ∧ Fun 𝑔) → Fun 𝐻)
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104   = wceq 1364  wcel 2160  {cab 2175  Vcvv 2752  cdif 3141  cun 3142  cin 3143  wss 3144  c0 3437   cuni 3824  ccnv 4640  dom cdm 4641  cres 4643  cima 4644  Fun wfun 5225
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 615  ax-in2 616  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-14 2163  ax-ext 2171  ax-sep 4136  ax-pow 4189  ax-pr 4224
This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1472  df-sb 1774  df-eu 2041  df-mo 2042  df-clab 2176  df-cleq 2182  df-clel 2185  df-nfc 2321  df-ral 2473  df-rex 2474  df-v 2754  df-dif 3146  df-un 3148  df-in 3150  df-ss 3157  df-nul 3438  df-pw 3592  df-sn 3613  df-pr 3614  df-op 3616  df-br 4019  df-opab 4080  df-id 4308  df-xp 4647  df-rel 4648  df-cnv 4649  df-co 4650  df-dm 4651  df-res 4653  df-fun 5233
This theorem is referenced by:  sbthlemi9  6982
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