Metamath Proof Explorer


Theorem dmopab2rex

Description: The domain of an ordered pair class abstraction with two nested restricted existential quantifiers. (Contributed by AV, 23-Oct-2023)

Ref Expression
Assertion dmopab2rex uUvVBXiIDWdomxy|uUvVx=Ay=BiIx=Cy=D=x|uUvVx=AiIx=C

Proof

Step Hyp Ref Expression
1 rexcom4 vVyz=Ay=ByvVz=Ay=B
2 rexcom4 iIyz=Cy=DyiIz=Cy=D
3 1 2 orbi12i vVyz=Ay=BiIyz=Cy=DyvVz=Ay=ByiIz=Cy=D
4 19.43 yvVz=Ay=BiIz=Cy=DyvVz=Ay=ByiIz=Cy=D
5 3 4 bitr4i vVyz=Ay=BiIyz=Cy=DyvVz=Ay=BiIz=Cy=D
6 5 rexbii uUvVyz=Ay=BiIyz=Cy=DuUyvVz=Ay=BiIz=Cy=D
7 rexcom4 uUyvVz=Ay=BiIz=Cy=DyuUvVz=Ay=BiIz=Cy=D
8 6 7 bitri uUvVyz=Ay=BiIyz=Cy=DyuUvVz=Ay=BiIz=Cy=D
9 simpl z=Ay=Bz=A
10 9 exlimiv yz=Ay=Bz=A
11 elisset BXyy=B
12 ibar z=Ay=Bz=Ay=B
13 12 bicomd z=Az=Ay=By=B
14 13 exbidv z=Ayz=Ay=Byy=B
15 11 14 syl5ibrcom BXz=Ayz=Ay=B
16 10 15 impbid2 BXyz=Ay=Bz=A
17 16 ralrexbid vVBXvVyz=Ay=BvVz=A
18 17 adantr vVBXiIDWvVyz=Ay=BvVz=A
19 simpl z=Cy=Dz=C
20 19 exlimiv yz=Cy=Dz=C
21 elisset DWyy=D
22 ibar z=Cy=Dz=Cy=D
23 22 bicomd z=Cz=Cy=Dy=D
24 23 exbidv z=Cyz=Cy=Dyy=D
25 21 24 syl5ibrcom DWz=Cyz=Cy=D
26 20 25 impbid2 DWyz=Cy=Dz=C
27 26 ralrexbid iIDWiIyz=Cy=DiIz=C
28 27 adantl vVBXiIDWiIyz=Cy=DiIz=C
29 18 28 orbi12d vVBXiIDWvVyz=Ay=BiIyz=Cy=DvVz=AiIz=C
30 29 ralrexbid uUvVBXiIDWuUvVyz=Ay=BiIyz=Cy=DuUvVz=AiIz=C
31 8 30 bitr3id uUvVBXiIDWyuUvVz=Ay=BiIz=Cy=DuUvVz=AiIz=C
32 eqeq1 x=zx=Az=A
33 32 anbi1d x=zx=Ay=Bz=Ay=B
34 33 rexbidv x=zvVx=Ay=BvVz=Ay=B
35 eqeq1 x=zx=Cz=C
36 35 anbi1d x=zx=Cy=Dz=Cy=D
37 36 rexbidv x=ziIx=Cy=DiIz=Cy=D
38 34 37 orbi12d x=zvVx=Ay=BiIx=Cy=DvVz=Ay=BiIz=Cy=D
39 38 rexbidv x=zuUvVx=Ay=BiIx=Cy=DuUvVz=Ay=BiIz=Cy=D
40 39 dmopabelb zVzdomxy|uUvVx=Ay=BiIx=Cy=DyuUvVz=Ay=BiIz=Cy=D
41 40 elv zdomxy|uUvVx=Ay=BiIx=Cy=DyuUvVz=Ay=BiIz=Cy=D
42 vex zV
43 32 rexbidv x=zvVx=AvVz=A
44 35 rexbidv x=ziIx=CiIz=C
45 43 44 orbi12d x=zvVx=AiIx=CvVz=AiIz=C
46 45 rexbidv x=zuUvVx=AiIx=CuUvVz=AiIz=C
47 42 46 elab zx|uUvVx=AiIx=CuUvVz=AiIz=C
48 31 41 47 3bitr4g uUvVBXiIDWzdomxy|uUvVx=Ay=BiIx=Cy=Dzx|uUvVx=AiIx=C
49 48 eqrdv uUvVBXiIDWdomxy|uUvVx=Ay=BiIx=Cy=D=x|uUvVx=AiIx=C