Metamath Proof Explorer


Theorem mreexexlem3d

Description: Base case of the induction in mreexexd . (Contributed by David Moews, 1-May-2017)

Ref Expression
Hypotheses mreexexlem2d.1
|- ( ph -> A e. ( Moore ` X ) )
mreexexlem2d.2
|- N = ( mrCls ` A )
mreexexlem2d.3
|- I = ( mrInd ` A )
mreexexlem2d.4
|- ( ph -> A. s e. ~P X A. y e. X A. z e. ( ( N ` ( s u. { y } ) ) \ ( N ` s ) ) y e. ( N ` ( s u. { z } ) ) )
mreexexlem2d.5
|- ( ph -> F C_ ( X \ H ) )
mreexexlem2d.6
|- ( ph -> G C_ ( X \ H ) )
mreexexlem2d.7
|- ( ph -> F C_ ( N ` ( G u. H ) ) )
mreexexlem2d.8
|- ( ph -> ( F u. H ) e. I )
mreexexlem3d.9
|- ( ph -> ( F = (/) \/ G = (/) ) )
Assertion mreexexlem3d
|- ( ph -> E. i e. ~P G ( F ~~ i /\ ( i u. H ) e. I ) )

Proof

Step Hyp Ref Expression
1 mreexexlem2d.1
 |-  ( ph -> A e. ( Moore ` X ) )
2 mreexexlem2d.2
 |-  N = ( mrCls ` A )
3 mreexexlem2d.3
 |-  I = ( mrInd ` A )
4 mreexexlem2d.4
 |-  ( ph -> A. s e. ~P X A. y e. X A. z e. ( ( N ` ( s u. { y } ) ) \ ( N ` s ) ) y e. ( N ` ( s u. { z } ) ) )
5 mreexexlem2d.5
 |-  ( ph -> F C_ ( X \ H ) )
6 mreexexlem2d.6
 |-  ( ph -> G C_ ( X \ H ) )
7 mreexexlem2d.7
 |-  ( ph -> F C_ ( N ` ( G u. H ) ) )
8 mreexexlem2d.8
 |-  ( ph -> ( F u. H ) e. I )
9 mreexexlem3d.9
 |-  ( ph -> ( F = (/) \/ G = (/) ) )
10 simpr
 |-  ( ( ph /\ F = (/) ) -> F = (/) )
11 1 adantr
 |-  ( ( ph /\ G = (/) ) -> A e. ( Moore ` X ) )
12 7 adantr
 |-  ( ( ph /\ G = (/) ) -> F C_ ( N ` ( G u. H ) ) )
13 simpr
 |-  ( ( ph /\ G = (/) ) -> G = (/) )
14 13 uneq1d
 |-  ( ( ph /\ G = (/) ) -> ( G u. H ) = ( (/) u. H ) )
15 uncom
 |-  ( H u. (/) ) = ( (/) u. H )
16 un0
 |-  ( H u. (/) ) = H
17 15 16 eqtr3i
 |-  ( (/) u. H ) = H
18 14 17 eqtrdi
 |-  ( ( ph /\ G = (/) ) -> ( G u. H ) = H )
19 18 fveq2d
 |-  ( ( ph /\ G = (/) ) -> ( N ` ( G u. H ) ) = ( N ` H ) )
20 12 19 sseqtrd
 |-  ( ( ph /\ G = (/) ) -> F C_ ( N ` H ) )
21 8 adantr
 |-  ( ( ph /\ G = (/) ) -> ( F u. H ) e. I )
22 3 11 21 mrissd
 |-  ( ( ph /\ G = (/) ) -> ( F u. H ) C_ X )
23 22 unssbd
 |-  ( ( ph /\ G = (/) ) -> H C_ X )
24 11 2 23 mrcssidd
 |-  ( ( ph /\ G = (/) ) -> H C_ ( N ` H ) )
25 20 24 unssd
 |-  ( ( ph /\ G = (/) ) -> ( F u. H ) C_ ( N ` H ) )
26 ssun2
 |-  H C_ ( F u. H )
27 26 a1i
 |-  ( ( ph /\ G = (/) ) -> H C_ ( F u. H ) )
28 11 2 3 25 27 21 mrissmrcd
 |-  ( ( ph /\ G = (/) ) -> ( F u. H ) = H )
29 ssequn1
 |-  ( F C_ H <-> ( F u. H ) = H )
30 28 29 sylibr
 |-  ( ( ph /\ G = (/) ) -> F C_ H )
31 5 adantr
 |-  ( ( ph /\ G = (/) ) -> F C_ ( X \ H ) )
32 30 31 ssind
 |-  ( ( ph /\ G = (/) ) -> F C_ ( H i^i ( X \ H ) ) )
33 disjdif
 |-  ( H i^i ( X \ H ) ) = (/)
34 32 33 sseqtrdi
 |-  ( ( ph /\ G = (/) ) -> F C_ (/) )
35 ss0b
 |-  ( F C_ (/) <-> F = (/) )
36 34 35 sylib
 |-  ( ( ph /\ G = (/) ) -> F = (/) )
37 10 36 9 mpjaodan
 |-  ( ph -> F = (/) )
38 0elpw
 |-  (/) e. ~P G
39 37 38 eqeltrdi
 |-  ( ph -> F e. ~P G )
40 1 elfvexd
 |-  ( ph -> X e. _V )
41 5 difss2d
 |-  ( ph -> F C_ X )
42 40 41 ssexd
 |-  ( ph -> F e. _V )
43 enrefg
 |-  ( F e. _V -> F ~~ F )
44 42 43 syl
 |-  ( ph -> F ~~ F )
45 breq2
 |-  ( i = F -> ( F ~~ i <-> F ~~ F ) )
46 uneq1
 |-  ( i = F -> ( i u. H ) = ( F u. H ) )
47 46 eleq1d
 |-  ( i = F -> ( ( i u. H ) e. I <-> ( F u. H ) e. I ) )
48 45 47 anbi12d
 |-  ( i = F -> ( ( F ~~ i /\ ( i u. H ) e. I ) <-> ( F ~~ F /\ ( F u. H ) e. I ) ) )
49 48 rspcev
 |-  ( ( F e. ~P G /\ ( F ~~ F /\ ( F u. H ) e. I ) ) -> E. i e. ~P G ( F ~~ i /\ ( i u. H ) e. I ) )
50 39 44 8 49 syl12anc
 |-  ( ph -> E. i e. ~P G ( F ~~ i /\ ( i u. H ) e. I ) )