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Theorem sbthlem1 3349
Description: Lemma for Schroeder-Bernstein Theorem.
Hypotheses
Ref Expression
sbthlem.1 |- A e. V
sbthlem.2 |- D = {x | (x (_ A /\ (g"(B \ (f"x))) (_ (A \ x))}
Assertion
Ref Expression
sbthlem1 |- U.D (_ (A \ (g"(B \ (f"U.D))))
Distinct variable group(s):   x,A   x,B   x,D   x,f   x,g

Proof of Theorem sbthlem1
StepHypRef Expression
1 unissb 1941 . 2 |- (U.D (_ (A \ (g"(B \ (f"U.D)))) <-> A.x e. D x (_ (A \ (g"(B \ (f"U.D)))))
2 sbthlem.2 . . . . 5 |- D = {x | (x (_ A /\ (g"(B \ (f"x))) (_ (A \ x))}
32cleqabi 1176 . . . 4 |- (x e. D <-> (x (_ A /\ (g"(B \ (f"x))) (_ (A \ x)))
4 ssconb 1598 . . . . . . . . 9 |- ((x (_ A /\ (g"(B \ (f"x))) (_ A) -> (x (_ (A \ (g"(B \ (f"x)))) <-> (g"(B \ (f"x))) (_ (A \ x)))
54biimprd 136 . . . . . . . 8 |- ((x (_ A /\ (g"(B \ (f"x))) (_ A) -> ((g"(B \ (f"x))) (_ (A \ x) -> x (_ (A \ (g"(B \ (f"x))))))
65exp 291 . . . . . . 7 |- (x (_ A -> ((g"(B \ (f"x))) (_ A -> ((g"(B \ (f"x))) (_ (A \ x) -> x (_ (A \ (g"(B \ (f"x)))))))
7 difss 1596 . . . . . . . 8 |- (A \ x) (_ A
8 sstr2 1510 . . . . . . . 8 |- ((g"(B \ (f"x))) (_ (A \ x) -> ((A \ x) (_ A -> (g"(B \ (f"x))) (_ A))
97, 8mpi 44 . . . . . . 7 |- ((g"(B \ (f"x))) (_ (A \ x) -> (g"(B \ (f"x))) (_ A)
106, 9syl5 22 . . . . . 6 |- (x (_ A -> ((g"(B \ (f"x))) (_ (A \ x) -> ((g"(B \ (f"x))) (_ (A \ x) -> x (_ (A \ (g"(B \ (f"x)))))))
1110pm2.43d 59 . . . . 5 |- (x (_ A -> ((g"(B \ (f"x))) (_ (A \ x) -> x (_ (A \ (g"(B \ (f"x))))))
1211imp 277 . . . 4 |- ((x (_ A /\ (g"(B \ (f"x))) (_ (A \ x)) -> x (_ (A \ (g"(B \ (f"x)))))
133, 12sylbi 174 . . 3 |- (x e. D -> x (_ (A \ (g"(B \ (f"x)))))
14 elssuni 1940 . . . . 5 |- (x e. D -> x (_ U.D)
15 imass2 2622 . . . . 5 |- (x (_ U.D -> (f"x) (_ (f"U.D))
16 sscon 1599 . . . . 5 |- ((f"x) (_ (f"U.D) -> (B \ (f"U.D)) (_ (B \ (f"x)))
1714, 15, 163syl 21 . . . 4 |- (x e. D -> (B \ (f"U.D)) (_ (B \ (f"x)))
18 imass2 2622 . . . 4 |- ((B \ (f"U.D)) (_ (B \ (f"x)) -> (g"(B \ (f"U.D))) (_ (g"(B \ (f"x))))
19 sscon 1599 . . . 4 |- ((g"(B \ (f"U.D))) (_ (g"(B \ (f"x))) -> (A \ (g"(B \ (f"x)))) (_ (A \ (g"(B \ (f"U.D)))))
2017, 18, 193syl 21 . . 3 |- (x e. D -> (A \ (g"(B \ (f"x)))) (_ (A \ (g"(B \ (f"U.D)))))
2113, 20sstrd 1513 . 2 |- (x e. D -> x (_ (A \ (g"(B \ (f"U.D)))))
221, 21mprgbir 1250 1 |- U.D (_ (A \ (g"(B \ (f"U.D))))
Colors of variables: wff set class
Syntax hints:   -> wi 2   /\ wa 196  {cab 1090   = wceq 1091   e. wcel 1092  Vcvv 1348   \ cdif 1484   (_ wss 1487  U.cuni 1919  "cima 2413
This theorem is referenced by:  sbthlem2 3350  sbthlem3 3351  sbthlem5 3353
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-13 804  ax-14 805  ax-16 922  ax-17 925  ax-ext 1074  ax-rep 1075  ax-pow 1077
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-ral 1205  df-v 1349  df-dif 1489  df-un 1490  df-in 1491  df-ss 1492  df-nul 1708  df-pw 1799  df-sn 1811  df-pr 1812  df-op 1815  df-uni 1920  df-br 2063  df-opab 2098  df-xp 2424  df-rel 2425  df-cnv 2426  df-dm 2428  df-rn 2429  df-res 2430  df-ima 2431
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