Step |
Hyp |
Ref |
Expression |
1 |
|
naddcl |
|- ( ( A e. On /\ B e. On ) -> ( A +no B ) e. On ) |
2 |
1
|
3adant3 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> ( A +no B ) e. On ) |
3 |
|
simp3 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> C e. On ) |
4 |
|
naddov3 |
|- ( ( A e. On /\ B e. On ) -> ( A +no B ) = |^| { a e. On | ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) C_ a } ) |
5 |
4
|
3adant3 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> ( A +no B ) = |^| { a e. On | ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) C_ a } ) |
6 |
|
intmin |
|- ( C e. On -> |^| { c e. On | C C_ c } = C ) |
7 |
6
|
eqcomd |
|- ( C e. On -> C = |^| { c e. On | C C_ c } ) |
8 |
7
|
3ad2ant3 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> C = |^| { c e. On | C C_ c } ) |
9 |
2 3 5 8
|
naddunif |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> ( ( A +no B ) +no C ) = |^| { x e. On | ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x } ) |
10 |
|
df-3an |
|- ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) <-> ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x ) /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) ) |
11 |
|
unss |
|- ( ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x ) <-> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) u. ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) C_ x ) |
12 |
|
ancom |
|- ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x ) <-> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x ) ) |
13 |
|
xpundir |
|- ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) = ( ( ( +no " ( { A } X. B ) ) X. { C } ) u. ( ( +no " ( A X. { B } ) ) X. { C } ) ) |
14 |
13
|
imaeq2i |
|- ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) = ( +no " ( ( ( +no " ( { A } X. B ) ) X. { C } ) u. ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) |
15 |
|
imaundi |
|- ( +no " ( ( ( +no " ( { A } X. B ) ) X. { C } ) u. ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) = ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) u. ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) |
16 |
14 15
|
eqtri |
|- ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) = ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) u. ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) |
17 |
16
|
sseq1i |
|- ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) C_ x <-> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) u. ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) ) C_ x ) |
18 |
11 12 17
|
3bitr4i |
|- ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x ) <-> ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) C_ x ) |
19 |
18
|
anbi1i |
|- ( ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x ) /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) <-> ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) C_ x /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) ) |
20 |
|
unss |
|- ( ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) C_ x /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) <-> ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x ) |
21 |
10 19 20
|
3bitrri |
|- ( ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x <-> ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) ) |
22 |
|
naddfn |
|- +no Fn ( On X. On ) |
23 |
|
fnfun |
|- ( +no Fn ( On X. On ) -> Fun +no ) |
24 |
22 23
|
ax-mp |
|- Fun +no |
25 |
|
imassrn |
|- ( +no " ( A X. { B } ) ) C_ ran +no |
26 |
|
naddf |
|- +no : ( On X. On ) --> On |
27 |
|
frn |
|- ( +no : ( On X. On ) --> On -> ran +no C_ On ) |
28 |
26 27
|
ax-mp |
|- ran +no C_ On |
29 |
25 28
|
sstri |
|- ( +no " ( A X. { B } ) ) C_ On |
30 |
|
simpl3 |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> C e. On ) |
31 |
30
|
snssd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> { C } C_ On ) |
32 |
|
xpss12 |
|- ( ( ( +no " ( A X. { B } ) ) C_ On /\ { C } C_ On ) -> ( ( +no " ( A X. { B } ) ) X. { C } ) C_ ( On X. On ) ) |
33 |
29 31 32
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( A X. { B } ) ) X. { C } ) C_ ( On X. On ) ) |
34 |
22
|
fndmi |
|- dom +no = ( On X. On ) |
35 |
33 34
|
sseqtrrdi |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( A X. { B } ) ) X. { C } ) C_ dom +no ) |
36 |
|
funimassov |
|- ( ( Fun +no /\ ( ( +no " ( A X. { B } ) ) X. { C } ) C_ dom +no ) -> ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x <-> A. p e. ( +no " ( A X. { B } ) ) A. c e. { C } ( p +no c ) e. x ) ) |
37 |
24 35 36
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x <-> A. p e. ( +no " ( A X. { B } ) ) A. c e. { C } ( p +no c ) e. x ) ) |
38 |
|
oveq2 |
|- ( c = C -> ( p +no c ) = ( p +no C ) ) |
39 |
38
|
eleq1d |
|- ( c = C -> ( ( p +no c ) e. x <-> ( p +no C ) e. x ) ) |
40 |
39
|
ralsng |
|- ( C e. On -> ( A. c e. { C } ( p +no c ) e. x <-> ( p +no C ) e. x ) ) |
41 |
30 40
|
syl |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. c e. { C } ( p +no c ) e. x <-> ( p +no C ) e. x ) ) |
42 |
41
|
ralbidv |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( A X. { B } ) ) A. c e. { C } ( p +no c ) e. x <-> A. p e. ( +no " ( A X. { B } ) ) ( p +no C ) e. x ) ) |
43 |
|
onss |
|- ( A e. On -> A C_ On ) |
44 |
43
|
3ad2ant1 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> A C_ On ) |
45 |
44
|
adantr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> A C_ On ) |
46 |
|
simpl2 |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> B e. On ) |
47 |
46
|
snssd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> { B } C_ On ) |
48 |
|
xpss12 |
|- ( ( A C_ On /\ { B } C_ On ) -> ( A X. { B } ) C_ ( On X. On ) ) |
49 |
45 47 48
|
syl2anc |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A X. { B } ) C_ ( On X. On ) ) |
50 |
|
oveq1 |
|- ( p = ( a +no b ) -> ( p +no C ) = ( ( a +no b ) +no C ) ) |
51 |
50
|
eleq1d |
|- ( p = ( a +no b ) -> ( ( p +no C ) e. x <-> ( ( a +no b ) +no C ) e. x ) ) |
52 |
51
|
imaeqalov |
|- ( ( +no Fn ( On X. On ) /\ ( A X. { B } ) C_ ( On X. On ) ) -> ( A. p e. ( +no " ( A X. { B } ) ) ( p +no C ) e. x <-> A. a e. A A. b e. { B } ( ( a +no b ) +no C ) e. x ) ) |
53 |
22 49 52
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( A X. { B } ) ) ( p +no C ) e. x <-> A. a e. A A. b e. { B } ( ( a +no b ) +no C ) e. x ) ) |
54 |
|
oveq2 |
|- ( b = B -> ( a +no b ) = ( a +no B ) ) |
55 |
54
|
oveq1d |
|- ( b = B -> ( ( a +no b ) +no C ) = ( ( a +no B ) +no C ) ) |
56 |
55
|
eleq1d |
|- ( b = B -> ( ( ( a +no b ) +no C ) e. x <-> ( ( a +no B ) +no C ) e. x ) ) |
57 |
56
|
ralsng |
|- ( B e. On -> ( A. b e. { B } ( ( a +no b ) +no C ) e. x <-> ( ( a +no B ) +no C ) e. x ) ) |
58 |
46 57
|
syl |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. b e. { B } ( ( a +no b ) +no C ) e. x <-> ( ( a +no B ) +no C ) e. x ) ) |
59 |
58
|
ralbidv |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. a e. A A. b e. { B } ( ( a +no b ) +no C ) e. x <-> A. a e. A ( ( a +no B ) +no C ) e. x ) ) |
60 |
53 59
|
bitrd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( A X. { B } ) ) ( p +no C ) e. x <-> A. a e. A ( ( a +no B ) +no C ) e. x ) ) |
61 |
37 42 60
|
3bitrd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x <-> A. a e. A ( ( a +no B ) +no C ) e. x ) ) |
62 |
|
imassrn |
|- ( +no " ( { A } X. B ) ) C_ ran +no |
63 |
62 28
|
sstri |
|- ( +no " ( { A } X. B ) ) C_ On |
64 |
|
xpss12 |
|- ( ( ( +no " ( { A } X. B ) ) C_ On /\ { C } C_ On ) -> ( ( +no " ( { A } X. B ) ) X. { C } ) C_ ( On X. On ) ) |
65 |
63 31 64
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( { A } X. B ) ) X. { C } ) C_ ( On X. On ) ) |
66 |
65 34
|
sseqtrrdi |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( { A } X. B ) ) X. { C } ) C_ dom +no ) |
67 |
|
funimassov |
|- ( ( Fun +no /\ ( ( +no " ( { A } X. B ) ) X. { C } ) C_ dom +no ) -> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x <-> A. p e. ( +no " ( { A } X. B ) ) A. c e. { C } ( p +no c ) e. x ) ) |
68 |
24 66 67
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x <-> A. p e. ( +no " ( { A } X. B ) ) A. c e. { C } ( p +no c ) e. x ) ) |
69 |
41
|
ralbidv |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( { A } X. B ) ) A. c e. { C } ( p +no c ) e. x <-> A. p e. ( +no " ( { A } X. B ) ) ( p +no C ) e. x ) ) |
70 |
|
simpl1 |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> A e. On ) |
71 |
70
|
snssd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> { A } C_ On ) |
72 |
|
onss |
|- ( B e. On -> B C_ On ) |
73 |
72
|
3ad2ant2 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> B C_ On ) |
74 |
73
|
adantr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> B C_ On ) |
75 |
|
xpss12 |
|- ( ( { A } C_ On /\ B C_ On ) -> ( { A } X. B ) C_ ( On X. On ) ) |
76 |
71 74 75
|
syl2anc |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( { A } X. B ) C_ ( On X. On ) ) |
77 |
51
|
imaeqalov |
|- ( ( +no Fn ( On X. On ) /\ ( { A } X. B ) C_ ( On X. On ) ) -> ( A. p e. ( +no " ( { A } X. B ) ) ( p +no C ) e. x <-> A. a e. { A } A. b e. B ( ( a +no b ) +no C ) e. x ) ) |
78 |
22 76 77
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( { A } X. B ) ) ( p +no C ) e. x <-> A. a e. { A } A. b e. B ( ( a +no b ) +no C ) e. x ) ) |
79 |
|
oveq1 |
|- ( a = A -> ( a +no b ) = ( A +no b ) ) |
80 |
79
|
oveq1d |
|- ( a = A -> ( ( a +no b ) +no C ) = ( ( A +no b ) +no C ) ) |
81 |
80
|
eleq1d |
|- ( a = A -> ( ( ( a +no b ) +no C ) e. x <-> ( ( A +no b ) +no C ) e. x ) ) |
82 |
81
|
ralbidv |
|- ( a = A -> ( A. b e. B ( ( a +no b ) +no C ) e. x <-> A. b e. B ( ( A +no b ) +no C ) e. x ) ) |
83 |
82
|
ralsng |
|- ( A e. On -> ( A. a e. { A } A. b e. B ( ( a +no b ) +no C ) e. x <-> A. b e. B ( ( A +no b ) +no C ) e. x ) ) |
84 |
70 83
|
syl |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. a e. { A } A. b e. B ( ( a +no b ) +no C ) e. x <-> A. b e. B ( ( A +no b ) +no C ) e. x ) ) |
85 |
78 84
|
bitrd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A. p e. ( +no " ( { A } X. B ) ) ( p +no C ) e. x <-> A. b e. B ( ( A +no b ) +no C ) e. x ) ) |
86 |
68 69 85
|
3bitrd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x <-> A. b e. B ( ( A +no b ) +no C ) e. x ) ) |
87 |
2
|
adantr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( A +no B ) e. On ) |
88 |
87
|
snssd |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> { ( A +no B ) } C_ On ) |
89 |
|
onss |
|- ( C e. On -> C C_ On ) |
90 |
89
|
3ad2ant3 |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> C C_ On ) |
91 |
90
|
adantr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> C C_ On ) |
92 |
|
xpss12 |
|- ( ( { ( A +no B ) } C_ On /\ C C_ On ) -> ( { ( A +no B ) } X. C ) C_ ( On X. On ) ) |
93 |
88 91 92
|
syl2anc |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( { ( A +no B ) } X. C ) C_ ( On X. On ) ) |
94 |
93 34
|
sseqtrrdi |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( { ( A +no B ) } X. C ) C_ dom +no ) |
95 |
|
funimassov |
|- ( ( Fun +no /\ ( { ( A +no B ) } X. C ) C_ dom +no ) -> ( ( +no " ( { ( A +no B ) } X. C ) ) C_ x <-> A. a e. { ( A +no B ) } A. c e. C ( a +no c ) e. x ) ) |
96 |
24 94 95
|
sylancr |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( { ( A +no B ) } X. C ) ) C_ x <-> A. a e. { ( A +no B ) } A. c e. C ( a +no c ) e. x ) ) |
97 |
|
ovex |
|- ( A +no B ) e. _V |
98 |
|
oveq1 |
|- ( a = ( A +no B ) -> ( a +no c ) = ( ( A +no B ) +no c ) ) |
99 |
98
|
eleq1d |
|- ( a = ( A +no B ) -> ( ( a +no c ) e. x <-> ( ( A +no B ) +no c ) e. x ) ) |
100 |
99
|
ralbidv |
|- ( a = ( A +no B ) -> ( A. c e. C ( a +no c ) e. x <-> A. c e. C ( ( A +no B ) +no c ) e. x ) ) |
101 |
97 100
|
ralsn |
|- ( A. a e. { ( A +no B ) } A. c e. C ( a +no c ) e. x <-> A. c e. C ( ( A +no B ) +no c ) e. x ) |
102 |
96 101
|
bitrdi |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( +no " ( { ( A +no B ) } X. C ) ) C_ x <-> A. c e. C ( ( A +no B ) +no c ) e. x ) ) |
103 |
61 86 102
|
3anbi123d |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( ( +no " ( ( +no " ( A X. { B } ) ) X. { C } ) ) C_ x /\ ( +no " ( ( +no " ( { A } X. B ) ) X. { C } ) ) C_ x /\ ( +no " ( { ( A +no B ) } X. C ) ) C_ x ) <-> ( A. a e. A ( ( a +no B ) +no C ) e. x /\ A. b e. B ( ( A +no b ) +no C ) e. x /\ A. c e. C ( ( A +no B ) +no c ) e. x ) ) ) |
104 |
21 103
|
bitrid |
|- ( ( ( A e. On /\ B e. On /\ C e. On ) /\ x e. On ) -> ( ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x <-> ( A. a e. A ( ( a +no B ) +no C ) e. x /\ A. b e. B ( ( A +no b ) +no C ) e. x /\ A. c e. C ( ( A +no B ) +no c ) e. x ) ) ) |
105 |
104
|
rabbidva |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> { x e. On | ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x } = { x e. On | ( A. a e. A ( ( a +no B ) +no C ) e. x /\ A. b e. B ( ( A +no b ) +no C ) e. x /\ A. c e. C ( ( A +no B ) +no c ) e. x ) } ) |
106 |
105
|
inteqd |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> |^| { x e. On | ( ( +no " ( ( ( +no " ( { A } X. B ) ) u. ( +no " ( A X. { B } ) ) ) X. { C } ) ) u. ( +no " ( { ( A +no B ) } X. C ) ) ) C_ x } = |^| { x e. On | ( A. a e. A ( ( a +no B ) +no C ) e. x /\ A. b e. B ( ( A +no b ) +no C ) e. x /\ A. c e. C ( ( A +no B ) +no c ) e. x ) } ) |
107 |
9 106
|
eqtrd |
|- ( ( A e. On /\ B e. On /\ C e. On ) -> ( ( A +no B ) +no C ) = |^| { x e. On | ( A. a e. A ( ( a +no B ) +no C ) e. x /\ A. b e. B ( ( A +no b ) +no C ) e. x /\ A. c e. C ( ( A +no B ) +no c ) e. x ) } ) |