Theorem ctiunct 13331

Description: A sequence of enumerations gives an enumeration of the union. We refer to "sequence of enumerations" rather than "countably many countable sets" because the hypothesis provides more than countability for each B ( x ): it refers to B ( x ) together with the G ( x ) which enumerates it. Theorem 8.1.19 of [AczelRathjen], p. 74.

For "countably many countable sets" the key hypothesis would be ( ph /\ x e. A ) -> E. g g : om -onto-> ( B ⊔ 1o ). This is almost omiunct 13335 (which uses countable choice) although that is for a countably infinite collection not any countable collection.

Compare with the case of two sets instead of countably many, as seen at unct 13333, which says that the union of two countable sets is countable .

The proof proceeds by mapping a natural number to a pair of natural numbers (by xpomen 13286) and using the first number to map to an element x of A and the second number to map to an element of B(x) . In this way we are able to map to every element of U_ x e. A B. Although it would be possible to work directly with countability expressed as F : om -onto-> ( A ⊔ 1o ), we instead use functions from subsets of the natural numbers via ctssdccl 7451 and ctssdc 7453.

(Contributed by Jim Kingdon, 31-Oct-2023.)

Hypotheses

Ref	Expression
ctiunct.a	|- ( ph -> F : om -onto-> ( A ⊔ 1o ) )
ctiunct.b	|- ( ( ph /\ x e. A ) -> G : om -onto-> ( B ⊔ 1o ) )

Assertion

Ref	Expression
ctiunct	|- ( ph -> E. h h : om -onto-> ( U_ x e. A B ⊔ 1o ) )

Distinct variable groups:   A, h, x   B, h   x, F   ph, x

Allowed substitution hints:   ph( h)   B( x)   F( h)   G( x, h)

Proof of Theorem ctiunct

Dummy variables j k n u z w are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		xpomen 13286	. . . . 5 |- ( om X. om ) ~~ om
2	1	ensymi 7069	. . . 4 |- om ~~ ( om X. om )
3		bren 7030	. . . 4 |- ( om ~~ ( om X. om ) <-> E. j j : om -1-1-onto-> ( om X. om ) )
4	2, 3	mpbi 145	. . 3 |- E. j j : om -1-1-onto-> ( om X. om )
5	4	a1i 9	. 2 |- ( ph -> E. j j : om -1-1-onto-> ( om X. om ) )
6		ctiunct.a	. . . . . . . 8 |- ( ph -> F : om -onto-> ( A ⊔ 1o ) )
7		eqid 2238	. . . . . . . 8 |- { w e. om | ( F ` w ) e. (inl " A ) } = { w e. om | ( F ` w ) e. (inl " A ) }
8		eqid 2238	. . . . . . . 8 |- ( `'inl o. F ) = ( `'inl o. F )
9	6, 7, 8	ctssdccl 7451	. . . . . . 7 |- ( ph -> ( { w e. om | ( F ` w ) e. (inl " A ) } C_ om /\ ( `'inl o. F ) : { w e. om | ( F ` w ) e. (inl " A ) } -onto-> A /\ A. n e. om DECID n e. { w e. om | ( F ` w ) e. (inl " A ) } ) )
10	9	simp1d 1040	. . . . . 6 |- ( ph -> { w e. om | ( F ` w ) e. (inl " A ) } C_ om )
11	10	adantr 276	. . . . 5 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> { w e. om | ( F ` w ) e. (inl " A ) } C_ om )
12	9	simp3d 1042	. . . . . 6 |- ( ph -> A. n e. om DECID n e. { w e. om | ( F ` w ) e. (inl " A ) } )
13	12	adantr 276	. . . . 5 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> A. n e. om DECID n e. { w e. om | ( F ` w ) e. (inl " A ) } )
14	9	simp2d 1041	. . . . . 6 |- ( ph -> ( `'inl o. F ) : { w e. om | ( F ` w ) e. (inl " A ) } -onto-> A )
15	14	adantr 276	. . . . 5 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> ( `'inl o. F ) : { w e. om | ( F ` w ) e. (inl " A ) } -onto-> A )
16		ctiunct.b	. . . . . . . 8 |- ( ( ph /\ x e. A ) -> G : om -onto-> ( B ⊔ 1o ) )
17		eqid 2238	. . . . . . . 8 |- { w e. om | ( G ` w ) e. (inl " B ) } = { w e. om | ( G ` w ) e. (inl " B ) }
18		eqid 2238	. . . . . . . 8 |- ( `'inl o. G ) = ( `'inl o. G )
19	16, 17, 18	ctssdccl 7451	. . . . . . 7 |- ( ( ph /\ x e. A ) -> ( { w e. om | ( G ` w ) e. (inl " B ) } C_ om /\ ( `'inl o. G ) : { w e. om | ( G ` w ) e. (inl " B ) } -onto-> B /\ A. n e. om DECID n e. { w e. om | ( G ` w ) e. (inl " B ) } ) )
20	19	simp1d 1040	. . . . . 6 |- ( ( ph /\ x e. A ) -> { w e. om | ( G ` w ) e. (inl " B ) } C_ om )
21	20	adantlr 481	. . . . 5 |- ( ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) /\ x e. A ) -> { w e. om | ( G ` w ) e. (inl " B ) } C_ om )
22	19	simp3d 1042	. . . . . 6 |- ( ( ph /\ x e. A ) -> A. n e. om DECID n e. { w e. om | ( G ` w ) e. (inl " B ) } )
23	22	adantlr 481	. . . . 5 |- ( ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) /\ x e. A ) -> A. n e. om DECID n e. { w e. om | ( G ` w ) e. (inl " B ) } )
24	19	simp2d 1041	. . . . . 6 |- ( ( ph /\ x e. A ) -> ( `'inl o. G ) : { w e. om | ( G ` w ) e. (inl " B ) } -onto-> B )
25	24	adantlr 481	. . . . 5 |- ( ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) /\ x e. A ) -> ( `'inl o. G ) : { w e. om | ( G ` w ) e. (inl " B ) } -onto-> B )
26		simpr 110	. . . . 5 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> j : om -1-1-onto-> ( om X. om ) )
27		eqid 2238	. . . . 5 |- { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) }
28	11, 13, 15, 21, 23, 25, 26, 27	ctiunctlemuom 13327	. . . 4 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } C_ om )
29		eqid 2238	. . . . . 6 |- ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) = ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) )
30		nfv 1581	. . . . . . . . 9 |- F/ x ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) }
31		nfcsb1v 3180	. . . . . . . . . 10 |- F/_ x [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) }
32	31	nfel2 2405	. . . . . . . . 9 |- F/ x ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) }
33	30, 32	nfan 1618	. . . . . . . 8 |- F/ x ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } )
34		nfcv 2392	. . . . . . . 8 |- F/_ x om
35	33, 34	nfrabw 2733	. . . . . . 7 |- F/_ x { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) }
36		nfcsb1v 3180	. . . . . . . 8 |- F/_ x [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G )
37		nfcv 2392	. . . . . . . 8 |- F/_ x ( 2nd ` ( j ` n ) )
38	36, 37	nffv 5705	. . . . . . 7 |- F/_ x ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) )
39	35, 38	nfmpt 4223	. . . . . 6 |- F/_ x ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) )
40	11, 13, 15, 21, 23, 25, 26, 27, 29, 39, 35	ctiunctlemfo 13330	. . . . 5 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B )
41		omex 4740	. . . . . . . 8 |- om e. _V
42	41	rabex 4280	. . . . . . 7 |- { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } e. _V
43	42	mptex 5943	. . . . . 6 |- ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) e. _V
44		foeq1 5611	. . . . . 6 |- ( k = ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) -> ( k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B <-> ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B ) )
45	43, 44	spcev 2920	. . . . 5 |- ( ( n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } |-> ( [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` n ) ) ) / x ]_ ( `'inl o. G ) ` ( 2nd ` ( j ` n ) ) ) ) : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B -> E. k k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B )
46	40, 45	syl 14	. . . 4 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> E. k k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B )
47	11, 13, 15, 21, 23, 25, 26, 27	ctiunctlemudc 13328	. . . 4 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> A. n e. om DECID n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } )
48		sseq1 3271	. . . . . 6 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( u C_ om <-> { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } C_ om ) )
49		foeq2 5612	. . . . . . 7 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( k : u -onto-> U_ x e. A B <-> k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B ) )
50	49	exbidv 1878	. . . . . 6 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( E. k k : u -onto-> U_ x e. A B <-> E. k k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B ) )
51		eleq2 2302	. . . . . . . 8 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( n e. u <-> n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } ) )
52	51	dcbid 850	. . . . . . 7 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> (DECID n e. u <-> DECID n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } ) )
53	52	ralbidv 2550	. . . . . 6 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( A. n e. om DECID n e. u <-> A. n e. om DECID n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } ) )
54	48, 50, 53	3anbi123d 1353	. . . . 5 |- ( u = { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -> ( ( u C_ om /\ E. k k : u -onto-> U_ x e. A B /\ A. n e. om DECID n e. u ) <-> ( { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } C_ om /\ E. k k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B /\ A. n e. om DECID n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } ) ) )
55	42, 54	spcev 2920	. . . 4 |- ( ( { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } C_ om /\ E. k k : { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } -onto-> U_ x e. A B /\ A. n e. om DECID n e. { z e. om | ( ( 1st ` ( j ` z ) ) e. { w e. om | ( F ` w ) e. (inl " A ) } /\ ( 2nd ` ( j ` z ) ) e. [_ ( ( `'inl o. F ) ` ( 1st ` ( j ` z ) ) ) / x ]_ { w e. om | ( G ` w ) e. (inl " B ) } ) } ) -> E. u ( u C_ om /\ E. k k : u -onto-> U_ x e. A B /\ A. n e. om DECID n e. u ) )
56	28, 46, 47, 55	syl3anc 1278	. . 3 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> E. u ( u C_ om /\ E. k k : u -onto-> U_ x e. A B /\ A. n e. om DECID n e. u ) )
57		ctssdc 7453	. . . 4 |- ( E. u ( u C_ om /\ E. k k : u -onto-> U_ x e. A B /\ A. n e. om DECID n e. u ) <-> E. k k : om -onto-> ( U_ x e. A B ⊔ 1o ) )
58		foeq1 5611	. . . . 5 |- ( k = h -> ( k : om -onto-> ( U_ x e. A B ⊔ 1o ) <-> h : om -onto-> ( U_ x e. A B ⊔ 1o ) ) )
59	58	cbvexv 1974	. . . 4 |- ( E. k k : om -onto-> ( U_ x e. A B ⊔ 1o ) <-> E. h h : om -onto-> ( U_ x e. A B ⊔ 1o ) )
60	57, 59	bitri 184	. . 3 |- ( E. u ( u C_ om /\ E. k k : u -onto-> U_ x e. A B /\ A. n e. om DECID n e. u ) <-> E. h h : om -onto-> ( U_ x e. A B ⊔ 1o ) )
61	56, 60	sylib 122	. 2 |- ( ( ph /\ j : om -1-1-onto-> ( om X. om ) ) -> E. h h : om -onto-> ( U_ x e. A B ⊔ 1o ) )
62	5, 61	exlimddv 1954	1 |- ( ph -> E. h h : om -onto-> ( U_ x e. A B ⊔ 1o ) )

This proof depends on syntax axioms:   -> wi 4   /\ wa 104  DECID wdc 846   /\ w3a 1009   = wceq 1402   E.wex 1545   e. wcel 2209   A.wral 2528   {crab 2532   [_csb 3147   C_ wss 3220   U_ciun 4012   class class class wbr 4130   |-> cmpt 4192   omcom 4737   X. cxp 4772   `'ccnv 4773   "cima 4777   o. ccom 4778   -onto->wfo 5375   -1-1-onto->wf1o 5376   ` cfv 5377   1stc1st 6372   2ndc2nd 6373   1oc1o 6680   ~~ cen 7020   ⊔ cdju 7377  inlcinl 7385

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-13 2211  ax-14 2212  ax-ext 2220  ax-coll 4246  ax-sep 4249  ax-nul 4259  ax-pow 4311  ax-pr 4346  ax-un 4578  ax-setind 4684  ax-iinf 4735  ax-cnex 8270  ax-resscn 8271  ax-1cn 8272  ax-1re 8273  ax-icn 8274  ax-addcl 8275  ax-addrcl 8276  ax-mulcl 8277  ax-mulrcl 8278  ax-addcom 8279  ax-mulcom 8280  ax-addass 8281  ax-mulass 8282  ax-distr 8283  ax-i2m1 8284  ax-0lt1 8285  ax-1rid 8286  ax-0id 8287  ax-rnegex 8288  ax-precex 8289  ax-cnre 8290  ax-pre-ltirr 8291  ax-pre-ltwlin 8292  ax-pre-lttrn 8293  ax-pre-apti 8294  ax-pre-ltadd 8295  ax-pre-mulgt0 8296  ax-pre-mulext 8297  ax-arch 8298

This proof depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-xor 1425  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-reu 2535  df-rmo 2536  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-if 3639  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-int 3971  df-iun 4014  df-br 4131  df-opab 4193  df-mpt 4194  df-tr 4230  df-id 4438  df-po 4441  df-iso 4442  df-iord 4511  df-on 4513  df-ilim 4514  df-suc 4516  df-iom 4738  df-xp 4780  df-rel 4781  df-cnv 4782  df-co 4783  df-dm 4784  df-rn 4785  df-res 4786  df-ima 4787  df-iota 5337  df-fun 5379  df-fn 5380  df-f 5381  df-f1 5382  df-fo 5383  df-f1o 5384  df-fv 5385  df-riota 6038  df-ov 6088  df-oprab 6089  df-mpo 6090  df-1st 6374  df-2nd 6375  df-recs 6576  df-frec 6662  df-1o 6687  df-er 6807  df-en 7023  df-dju 7378  df-inl 7387  df-inr 7388  df-case 7424  df-pnf 8362  df-mnf 8363  df-xr 8364  df-ltxr 8365  df-le 8366  df-sub 8499  df-neg 8500  df-reap 8903  df-ap 8910  df-div 9003  df-inn 9305  df-2 9363  df-n0 9564  df-z 9645  df-uz 9922  df-q 10020  df-rp 10055  df-fz 10412  df-fl 10705  df-mod 10760  df-seqfrec 10885  df-exp 10976  df-dvds 12555

This theorem is used by:  ctiunctal  13332  unct  13333