Theorem subctctexmid 13520

Description: If every subcountable set is countable and Markov's principle holds, excluded middle follows. Proposition 2.6 of [BauerSwan], p. 14:4. The proof is taken from that paper. (Contributed by Jim Kingdon, 29-Nov-2023.)

Hypotheses

Ref	Expression
subctctexmid.x	|- ( ph -> A. x ( E. s ( s C_ om /\ E. f f : s -onto-> x ) -> E. g g : om -onto-> ( x ⊔ 1o ) ) )
subctctexmid.mk	|- ( ph -> om e. Markov )

Assertion

Ref	Expression
subctctexmid	|- ( ph -> EXMID )

Distinct variable groups:   f, s, x   ph, g   x, g

Allowed substitution hints:   ph( x, f, s)

Proof of Theorem subctctexmid

Dummy variables y z h n w are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		subctctexmid.x	. . . . 5 |- ( ph -> A. x ( E. s ( s C_ om /\ E. f f : s -onto-> x ) -> E. g g : om -onto-> ( x ⊔ 1o ) ) )
2		omex 4546	. . . . . . . 8 |- om e. _V
3	2	rabex 4104	. . . . . . 7 |- { z e. om | y = { (/) } } e. _V
4	3	a1i 9	. . . . . 6 |- ( ph -> { z e. om | y = { (/) } } e. _V )
5		ssrab2 3209	. . . . . . 7 |- { z e. om | y = { (/) } } C_ om
6		f1oi 5445	. . . . . . . . 9 |- ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -1-1-onto-> { z e. om | y = { (/) } }
7		f1ofo 5414	. . . . . . . . 9 |- ( ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -1-1-onto-> { z e. om | y = { (/) } } -> ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } )
8	6, 7	ax-mp 5	. . . . . . . 8 |- ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } }
9		resiexg 4904	. . . . . . . . . 10 |- ( { z e. om | y = { (/) } } e. _V -> ( _I |` { z e. om | y = { (/) } } ) e. _V )
10	3, 9	ax-mp 5	. . . . . . . . 9 |- ( _I |` { z e. om | y = { (/) } } ) e. _V
11		foeq1 5381	. . . . . . . . 9 |- ( f = ( _I |` { z e. om | y = { (/) } } ) -> ( f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } <-> ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } ) )
12	10, 11	spcev 2804	. . . . . . . 8 |- ( ( _I |` { z e. om | y = { (/) } } ) : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } -> E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } )
13	8, 12	ax-mp 5	. . . . . . 7 |- E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } }
14	5, 13	pm3.2i 270	. . . . . 6 |- ( { z e. om | y = { (/) } } C_ om /\ E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } )
15		sseq1 3147	. . . . . . . 8 |- ( s = { z e. om | y = { (/) } } -> ( s C_ om <-> { z e. om | y = { (/) } } C_ om ) )
16		foeq2 5382	. . . . . . . . 9 |- ( s = { z e. om | y = { (/) } } -> ( f : s -onto-> { z e. om | y = { (/) } } <-> f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } ) )
17	16	exbidv 1802	. . . . . . . 8 |- ( s = { z e. om | y = { (/) } } -> ( E. f f : s -onto-> { z e. om | y = { (/) } } <-> E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } ) )
18	15, 17	anbi12d 465	. . . . . . 7 |- ( s = { z e. om | y = { (/) } } -> ( ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) <-> ( { z e. om | y = { (/) } } C_ om /\ E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } ) ) )
19	18	spcegv 2797	. . . . . 6 |- ( { z e. om | y = { (/) } } e. _V -> ( ( { z e. om | y = { (/) } } C_ om /\ E. f f : { z e. om | y = { (/) } } -onto-> { z e. om | y = { (/) } } ) -> E. s ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) ) )
20	4, 14, 19	mpisyl 1423	. . . . 5 |- ( ph -> E. s ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) )
21		foeq3 5383	. . . . . . . . . 10 |- ( x = { z e. om | y = { (/) } } -> ( f : s -onto-> x <-> f : s -onto-> { z e. om | y = { (/) } } ) )
22	21	exbidv 1802	. . . . . . . . 9 |- ( x = { z e. om | y = { (/) } } -> ( E. f f : s -onto-> x <-> E. f f : s -onto-> { z e. om | y = { (/) } } ) )
23	22	anbi2d 460	. . . . . . . 8 |- ( x = { z e. om | y = { (/) } } -> ( ( s C_ om /\ E. f f : s -onto-> x ) <-> ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) ) )
24	23	exbidv 1802	. . . . . . 7 |- ( x = { z e. om | y = { (/) } } -> ( E. s ( s C_ om /\ E. f f : s -onto-> x ) <-> E. s ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) ) )
25		djueq1 6970	. . . . . . . . 9 |- ( x = { z e. om | y = { (/) } } -> ( x ⊔ 1o ) = ( { z e. om | y = { (/) } } ⊔ 1o ) )
26		foeq3 5383	. . . . . . . . 9 |- ( ( x ⊔ 1o ) = ( { z e. om | y = { (/) } } ⊔ 1o ) -> ( g : om -onto-> ( x ⊔ 1o ) <-> g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) )
27	25, 26	syl 14	. . . . . . . 8 |- ( x = { z e. om | y = { (/) } } -> ( g : om -onto-> ( x ⊔ 1o ) <-> g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) )
28	27	exbidv 1802	. . . . . . 7 |- ( x = { z e. om | y = { (/) } } -> ( E. g g : om -onto-> ( x ⊔ 1o ) <-> E. g g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) )
29	24, 28	imbi12d 233	. . . . . 6 |- ( x = { z e. om | y = { (/) } } -> ( ( E. s ( s C_ om /\ E. f f : s -onto-> x ) -> E. g g : om -onto-> ( x ⊔ 1o ) ) <-> ( E. s ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) -> E. g g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) ) )
30	3, 29	spcv 2803	. . . . 5 |- ( A. x ( E. s ( s C_ om /\ E. f f : s -onto-> x ) -> E. g g : om -onto-> ( x ⊔ 1o ) ) -> ( E. s ( s C_ om /\ E. f f : s -onto-> { z e. om | y = { (/) } } ) -> E. g g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) )
31	1, 20, 30	sylc 62	. . . 4 |- ( ph -> E. g g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) )
32		fveq1 5460	. . . . . . . . . . . 12 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( h ` n ) = ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) )
33	32	eqeq1d 2163	. . . . . . . . . . 11 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( ( h ` n ) = 1o <-> ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
34	33	rexbidv 2455	. . . . . . . . . 10 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( E. n e. om ( h ` n ) = 1o <-> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
35	34	notbid 657	. . . . . . . . 9 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( -. E. n e. om ( h ` n ) = 1o <-> -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
36	35	notbid 657	. . . . . . . 8 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( -. -. E. n e. om ( h ` n ) = 1o <-> -. -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
37	36, 34	imbi12d 233	. . . . . . 7 |- ( h = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) -> ( ( -. -. E. n e. om ( h ` n ) = 1o -> E. n e. om ( h ` n ) = 1o ) <-> ( -. -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o -> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) ) )
38		subctctexmid.mk	. . . . . . . . 9 |- ( ph -> om e. Markov )
39		ismkvnex 7077	. . . . . . . . . 10 |- ( om e. Markov -> ( om e. Markov <-> A. h e. ( 2o ^m om ) ( -. -. E. n e. om ( h ` n ) = 1o -> E. n e. om ( h ` n ) = 1o ) ) )
40	38, 39	syl 14	. . . . . . . . 9 |- ( ph -> ( om e. Markov <-> A. h e. ( 2o ^m om ) ( -. -. E. n e. om ( h ` n ) = 1o -> E. n e. om ( h ` n ) = 1o ) ) )
41	38, 40	mpbid 146	. . . . . . . 8 |- ( ph -> A. h e. ( 2o ^m om ) ( -. -. E. n e. om ( h ` n ) = 1o -> E. n e. om ( h ` n ) = 1o ) )
42	41	adantr 274	. . . . . . 7 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> A. h e. ( 2o ^m om ) ( -. -. E. n e. om ( h ` n ) = 1o -> E. n e. om ( h ` n ) = 1o ) )
43		1lt2o 6379	. . . . . . . . . . . 12 |- 1o e. 2o
44	43	a1i 9	. . . . . . . . . . 11 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ ( 1st ` ( g ` n ) ) = (/) ) -> 1o e. 2o )
45		0lt2o 6378	. . . . . . . . . . . 12 |- (/) e. 2o
46	45	a1i 9	. . . . . . . . . . 11 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ -. ( 1st ` ( g ` n ) ) = (/) ) -> (/) e. 2o )
47		simplr 520	. . . . . . . . . . . . . . 15 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) )
48		fof 5385	. . . . . . . . . . . . . . 15 |- ( g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) -> g : om --> ( { z e. om | y = { (/) } } ⊔ 1o ) )
49	47, 48	syl 14	. . . . . . . . . . . . . 14 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> g : om --> ( { z e. om | y = { (/) } } ⊔ 1o ) )
50		simpr 109	. . . . . . . . . . . . . 14 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> n e. om )
51	49, 50	ffvelrnd 5596	. . . . . . . . . . . . 13 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( g ` n ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) )
52		eldju1st 7001	. . . . . . . . . . . . 13 |- ( ( g ` n ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) -> ( ( 1st ` ( g ` n ) ) = (/) \/ ( 1st ` ( g ` n ) ) = 1o ) )
53	51, 52	syl 14	. . . . . . . . . . . 12 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( ( 1st ` ( g ` n ) ) = (/) \/ ( 1st ` ( g ` n ) ) = 1o ) )
54		1n0 6369	. . . . . . . . . . . . . . . 16 |- 1o =/= (/)
55	54	neii 2326	. . . . . . . . . . . . . . 15 |- -. 1o = (/)
56		eqeq1 2161	. . . . . . . . . . . . . . 15 |- ( ( 1st ` ( g ` n ) ) = 1o -> ( ( 1st ` ( g ` n ) ) = (/) <-> 1o = (/) ) )
57	55, 56	mtbiri 665	. . . . . . . . . . . . . 14 |- ( ( 1st ` ( g ` n ) ) = 1o -> -. ( 1st ` ( g ` n ) ) = (/) )
58	57	orim2i 751	. . . . . . . . . . . . 13 |- ( ( ( 1st ` ( g ` n ) ) = (/) \/ ( 1st ` ( g ` n ) ) = 1o ) -> ( ( 1st ` ( g ` n ) ) = (/) \/ -. ( 1st ` ( g ` n ) ) = (/) ) )
59		df-dc 821	. . . . . . . . . . . . 13 |- (DECID ( 1st ` ( g ` n ) ) = (/) <-> ( ( 1st ` ( g ` n ) ) = (/) \/ -. ( 1st ` ( g ` n ) ) = (/) ) )
60	58, 59	sylibr 133	. . . . . . . . . . . 12 |- ( ( ( 1st ` ( g ` n ) ) = (/) \/ ( 1st ` ( g ` n ) ) = 1o ) -> DECID ( 1st ` ( g ` n ) ) = (/) )
61	53, 60	syl 14	. . . . . . . . . . 11 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> DECID ( 1st ` ( g ` n ) ) = (/) )
62	44, 46, 61	ifcldadc 3530	. . . . . . . . . 10 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) e. 2o )
63	62	fmpttd 5615	. . . . . . . . 9 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( n e. om |-> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) ) : om --> 2o )
64		2fveq3 5466	. . . . . . . . . . . . . 14 |- ( w = n -> ( 1st ` ( g ` w ) ) = ( 1st ` ( g ` n ) ) )
65	64	eqeq1d 2163	. . . . . . . . . . . . 13 |- ( w = n -> ( ( 1st ` ( g ` w ) ) = (/) <-> ( 1st ` ( g ` n ) ) = (/) ) )
66	65	ifbid 3522	. . . . . . . . . . . 12 |- ( w = n -> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) )
67		eqcom 2156	. . . . . . . . . . . 12 |- ( w = n <-> n = w )
68		eqcom 2156	. . . . . . . . . . . 12 |- ( if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) <-> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) )
69	66, 67, 68	3imtr3i 199	. . . . . . . . . . 11 |- ( n = w -> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) )
70	69	cbvmptv 4056	. . . . . . . . . 10 |- ( n e. om |-> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) ) = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) )
71	70	feq1i 5305	. . . . . . . . 9 |- ( ( n e. om |-> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) ) : om --> 2o <-> ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) : om --> 2o )
72	63, 71	sylib 121	. . . . . . . 8 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) : om --> 2o )
73		2onn 6457	. . . . . . . . . 10 |- 2o e. om
74	73	elexi 2721	. . . . . . . . 9 |- 2o e. _V
75	74, 2	elmap 6611	. . . . . . . 8 |- ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) e. ( 2o ^m om ) <-> ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) : om --> 2o )
76	72, 75	sylibr 133	. . . . . . 7 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) e. ( 2o ^m om ) )
77	37, 42, 76	rspcdva 2818	. . . . . 6 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( -. -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o -> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
78		eqid 2154	. . . . . . . . . . . . 13 |- ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) = ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) )
79	78, 66, 50, 62	fvmptd3 5554	. . . . . . . . . . . 12 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) )
80	79	eqeq1d 2163	. . . . . . . . . . 11 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o <-> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) )
81	51	adantr 274	. . . . . . . . . . . . . . 15 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> ( g ` n ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) )
82		simpr 109	. . . . . . . . . . . . . . . . 17 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o )
83	82	eqcomd 2160	. . . . . . . . . . . . . . . 16 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> 1o = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) )
84		eqifdc 3535	. . . . . . . . . . . . . . . . . . 19 |- (DECID ( 1st ` ( g ` n ) ) = (/) -> ( 1o = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) <-> ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) \/ ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) ) ) )
85	61, 84	syl 14	. . . . . . . . . . . . . . . . . 18 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( 1o = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) <-> ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) \/ ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) ) ) )
86		eqid 2154	. . . . . . . . . . . . . . . . . . 19 |- 1o = 1o
87		orcom 718	. . . . . . . . . . . . . . . . . . . 20 |- ( ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) \/ ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) ) <-> ( ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) \/ ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) ) )
88	55	intnan 915	. . . . . . . . . . . . . . . . . . . . 21 |- -. ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) )
89		biorf 734	. . . . . . . . . . . . . . . . . . . . 21 |- ( -. ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) -> ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) <-> ( ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) \/ ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) ) ) )
90	88, 89	ax-mp 5	. . . . . . . . . . . . . . . . . . . 20 |- ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) <-> ( ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) \/ ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) ) )
91	87, 90	bitr4i 186	. . . . . . . . . . . . . . . . . . 19 |- ( ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) \/ ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) ) <-> ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) )
92	86, 91	mpbiran2 926	. . . . . . . . . . . . . . . . . 18 |- ( ( ( ( 1st ` ( g ` n ) ) = (/) /\ 1o = 1o ) \/ ( -. ( 1st ` ( g ` n ) ) = (/) /\ 1o = (/) ) ) <-> ( 1st ` ( g ` n ) ) = (/) )
93	85, 92	bitrdi 195	. . . . . . . . . . . . . . . . 17 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( 1o = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) <-> ( 1st ` ( g ` n ) ) = (/) ) )
94	93	adantr 274	. . . . . . . . . . . . . . . 16 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> ( 1o = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) <-> ( 1st ` ( g ` n ) ) = (/) ) )
95	83, 94	mpbid 146	. . . . . . . . . . . . . . 15 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> ( 1st ` ( g ` n ) ) = (/) )
96		eldju2ndl 7002	. . . . . . . . . . . . . . 15 |- ( ( ( g ` n ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) /\ ( 1st ` ( g ` n ) ) = (/) ) -> ( 2nd ` ( g ` n ) ) e. { z e. om | y = { (/) } } )
97	81, 95, 96	syl2anc 409	. . . . . . . . . . . . . 14 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> ( 2nd ` ( g ` n ) ) e. { z e. om | y = { (/) } } )
98		biidd 171	. . . . . . . . . . . . . . 15 |- ( z = ( 2nd ` ( g ` n ) ) -> ( y = { (/) } <-> y = { (/) } ) )
99	98	elrab 2864	. . . . . . . . . . . . . 14 |- ( ( 2nd ` ( g ` n ) ) e. { z e. om | y = { (/) } } <-> ( ( 2nd ` ( g ` n ) ) e. om /\ y = { (/) } ) )
100	97, 99	sylib 121	. . . . . . . . . . . . 13 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> ( ( 2nd ` ( g ` n ) ) e. om /\ y = { (/) } ) )
101	100	simprd 113	. . . . . . . . . . . 12 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) /\ if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o ) -> y = { (/) } )
102	101	ex 114	. . . . . . . . . . 11 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o -> y = { (/) } ) )
103	80, 102	sylbid 149	. . . . . . . . . 10 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ n e. om ) -> ( ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o -> y = { (/) } ) )
104	103	rexlimdva 2571	. . . . . . . . 9 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o -> y = { (/) } ) )
105		simplr 520	. . . . . . . . . . . 12 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) )
106		biidd 171	. . . . . . . . . . . . . 14 |- ( z = (/) -> ( y = { (/) } <-> y = { (/) } ) )
107		peano1 4547	. . . . . . . . . . . . . . 15 |- (/) e. om
108	107	a1i 9	. . . . . . . . . . . . . 14 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> (/) e. om )
109		simpr 109	. . . . . . . . . . . . . 14 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> y = { (/) } )
110	106, 108, 109	elrabd 2866	. . . . . . . . . . . . 13 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> (/) e. { z e. om | y = { (/) } } )
111		djulcl 6981	. . . . . . . . . . . . 13 |- ( (/) e. { z e. om | y = { (/) } } -> (inl ` (/) ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) )
112	110, 111	syl 14	. . . . . . . . . . . 12 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> (inl ` (/) ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) )
113		foelrn 5694	. . . . . . . . . . . 12 |- ( ( g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) /\ (inl ` (/) ) e. ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> E. n e. om (inl ` (/) ) = ( g ` n ) )
114	105, 112, 113	syl2anc 409	. . . . . . . . . . 11 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> E. n e. om (inl ` (/) ) = ( g ` n ) )
115	79	adantlr 469	. . . . . . . . . . . . . 14 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) /\ n e. om ) -> ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) )
116		1stinl 7004	. . . . . . . . . . . . . . . . 17 |- ( (/) e. om -> ( 1st ` (inl ` (/) ) ) = (/) )
117	107, 116	ax-mp 5	. . . . . . . . . . . . . . . 16 |- ( 1st ` (inl ` (/) ) ) = (/)
118		fveq2 5461	. . . . . . . . . . . . . . . 16 |- ( (inl ` (/) ) = ( g ` n ) -> ( 1st ` (inl ` (/) ) ) = ( 1st ` ( g ` n ) ) )
119	117, 118	syl5reqr 2202	. . . . . . . . . . . . . . 15 |- ( (inl ` (/) ) = ( g ` n ) -> ( 1st ` ( g ` n ) ) = (/) )
120	119	iftrued 3508	. . . . . . . . . . . . . 14 |- ( (inl ` (/) ) = ( g ` n ) -> if ( ( 1st ` ( g ` n ) ) = (/) , 1o , (/) ) = 1o )
121	115, 120	sylan9eq 2207	. . . . . . . . . . . . 13 |- ( ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) /\ n e. om ) /\ (inl ` (/) ) = ( g ` n ) ) -> ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o )
122	121	ex 114	. . . . . . . . . . . 12 |- ( ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) /\ n e. om ) -> ( (inl ` (/) ) = ( g ` n ) -> ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
123	122	reximdva 2556	. . . . . . . . . . 11 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> ( E. n e. om (inl ` (/) ) = ( g ` n ) -> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
124	114, 123	mpd 13	. . . . . . . . . 10 |- ( ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) /\ y = { (/) } ) -> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o )
125	124	ex 114	. . . . . . . . 9 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( y = { (/) } -> E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o ) )
126	104, 125	impbid 128	. . . . . . . 8 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o <-> y = { (/) } ) )
127	126	notbid 657	. . . . . . 7 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o <-> -. y = { (/) } ) )
128	127	notbid 657	. . . . . 6 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( -. -. E. n e. om ( ( w e. om |-> if ( ( 1st ` ( g ` w ) ) = (/) , 1o , (/) ) ) ` n ) = 1o <-> -. -. y = { (/) } ) )
129	77, 128, 126	3imtr3d 201	. . . . 5 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> ( -. -. y = { (/) } -> y = { (/) } ) )
130		df-stab 817	. . . . 5 |- (STAB y = { (/) } <-> ( -. -. y = { (/) } -> y = { (/) } ) )
131	129, 130	sylibr 133	. . . 4 |- ( ( ph /\ g : om -onto-> ( { z e. om | y = { (/) } } ⊔ 1o ) ) -> STAB y = { (/) } )
132	31, 131	exlimddv 1875	. . 3 |- ( ph -> STAB y = { (/) } )
133	132	adantr 274	. 2 |- ( ( ph /\ y C_ { (/) } ) -> STAB y = { (/) } )
134	133	exmid1stab 13519	1 |- ( ph -> EXMID )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 103   <-> wb 104   \/ wo 698  STAB wstab 816  DECID wdc 820   A.wal 1330   = wceq 1332   E.wex 1469   e. wcel 2125   A.wral 2432   E.wrex 2433   {crab 2436   _Vcvv 2709   C_ wss 3098   (/)c0 3390   ifcif 3501   {csn 3556   |-> cmpt 4021  EXMIDwem 4150   _I cid 4243   omcom 4543   |` cres 4581   -->wf 5159   -onto->wfo 5161   -1-1-onto->wf1o 5162   ` cfv 5163  (class class class)co 5814   1stc1st 6076   2ndc2nd 6077   1oc1o 6346   2oc2o 6347   ^m cmap 6582   ⊔ cdju 6967  inlcinl 6975  Markovcmarkov 7073

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1481  ax-10 1482  ax-11 1483  ax-i12 1484  ax-bndl 1486  ax-4 1487  ax-17 1503  ax-i9 1507  ax-ial 1511  ax-i5r 1512  ax-13 2127  ax-14 2128  ax-ext 2136  ax-sep 4078  ax-nul 4086  ax-pow 4130  ax-pr 4164  ax-un 4388  ax-setind 4490  ax-iinf 4541

This theorem depends on definitions:  df-bi 116  df-stab 817  df-dc 821  df-3an 965  df-tru 1335  df-fal 1338  df-nf 1438  df-sb 1740  df-eu 2006  df-mo 2007  df-clab 2141  df-cleq 2147  df-clel 2150  df-nfc 2285  df-ne 2325  df-ral 2437  df-rex 2438  df-rab 2441  df-v 2711  df-sbc 2934  df-csb 3028  df-dif 3100  df-un 3102  df-in 3104  df-ss 3111  df-nul 3391  df-if 3502  df-pw 3541  df-sn 3562  df-pr 3563  df-op 3565  df-uni 3769  df-int 3804  df-br 3962  df-opab 4022  df-mpt 4023  df-tr 4059  df-exmid 4151  df-id 4248  df-iord 4321  df-on 4323  df-suc 4326  df-iom 4544  df-xp 4585  df-rel 4586  df-cnv 4587  df-co 4588  df-dm 4589  df-rn 4590  df-res 4591  df-ima 4592  df-iota 5128  df-fun 5165  df-fn 5166  df-f 5167  df-f1 5168  df-fo 5169  df-f1o 5170  df-fv 5171  df-ov 5817  df-oprab 5818  df-mpo 5819  df-1st 6078  df-2nd 6079  df-1o 6353  df-2o 6354  df-map 6584  df-dju 6968  df-inl 6977  df-inr 6978  df-markov 7074

This theorem is referenced by: (None)