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Theorem sbthlem1 6951
Description: Lemma for isbth 6961. (Contributed by NM, 22-Mar-1998.)
Hypotheses
Ref Expression
sbthlem.1 𝐴 ∈ V
sbthlem.2 𝐷 = {𝑥 ∣ (𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥))}
Assertion
Ref Expression
sbthlem1 𝐷 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷))))
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐷   𝑥,𝑓   𝑥,𝑔
Allowed substitution hints:   𝐴(𝑓,𝑔)   𝐵(𝑓,𝑔)   𝐷(𝑓,𝑔)

Proof of Theorem sbthlem1
StepHypRef Expression
1 unissb 3838 . 2 ( 𝐷 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷)))) ↔ ∀𝑥𝐷 𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷)))))
2 sbthlem.2 . . . . 5 𝐷 = {𝑥 ∣ (𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥))}
32abeq2i 2288 . . . 4 (𝑥𝐷 ↔ (𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥)))
4 difss2 3263 . . . . . . 7 ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥) → (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ 𝐴)
5 ssconb 3268 . . . . . . . 8 ((𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ 𝐴) → (𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))) ↔ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥)))
65exbiri 382 . . . . . . 7 (𝑥𝐴 → ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ 𝐴 → ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥) → 𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))))))
74, 6syl5 32 . . . . . 6 (𝑥𝐴 → ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥) → ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥) → 𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))))))
87pm2.43d 50 . . . . 5 (𝑥𝐴 → ((𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥) → 𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥))))))
98imp 124 . . . 4 ((𝑥𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) ⊆ (𝐴𝑥)) → 𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))))
103, 9sylbi 121 . . 3 (𝑥𝐷𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))))
11 elssuni 3836 . . . . 5 (𝑥𝐷𝑥 𝐷)
12 imass2 5001 . . . . 5 (𝑥 𝐷 → (𝑓𝑥) ⊆ (𝑓 𝐷))
13 sscon 3269 . . . . 5 ((𝑓𝑥) ⊆ (𝑓 𝐷) → (𝐵 ∖ (𝑓 𝐷)) ⊆ (𝐵 ∖ (𝑓𝑥)))
1411, 12, 133syl 17 . . . 4 (𝑥𝐷 → (𝐵 ∖ (𝑓 𝐷)) ⊆ (𝐵 ∖ (𝑓𝑥)))
15 imass2 5001 . . . 4 ((𝐵 ∖ (𝑓 𝐷)) ⊆ (𝐵 ∖ (𝑓𝑥)) → (𝑔 “ (𝐵 ∖ (𝑓 𝐷))) ⊆ (𝑔 “ (𝐵 ∖ (𝑓𝑥))))
16 sscon 3269 . . . 4 ((𝑔 “ (𝐵 ∖ (𝑓 𝐷))) ⊆ (𝑔 “ (𝐵 ∖ (𝑓𝑥))) → (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))) ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷)))))
1714, 15, 163syl 17 . . 3 (𝑥𝐷 → (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓𝑥)))) ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷)))))
1810, 17sstrd 3165 . 2 (𝑥𝐷𝑥 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷)))))
191, 18mprgbir 2535 1 𝐷 ⊆ (𝐴 ∖ (𝑔 “ (𝐵 ∖ (𝑓 𝐷))))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104   = wceq 1353  wcel 2148  {cab 2163  Vcvv 2737  cdif 3126  wss 3129   cuni 3808  cima 4627
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 614  ax-in2 615  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-v 2739  df-dif 3131  df-un 3133  df-in 3135  df-ss 3142  df-sn 3598  df-pr 3599  df-op 3601  df-uni 3809  df-br 4002  df-opab 4063  df-xp 4630  df-cnv 4632  df-dm 4634  df-rn 4635  df-res 4636  df-ima 4637
This theorem is referenced by:  sbthlem2  6952  sbthlemi3  6953  sbthlemi5  6955
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