| Step |
Hyp |
Ref |
Expression |
| 1 |
|
simpl3 |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> C e. W ) |
| 2 |
|
prfi |
|- { A , B } e. Fin |
| 3 |
2
|
a1i |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> { A , B } e. Fin ) |
| 4 |
|
elprg |
|- ( C e. W -> ( C e. { A , B } <-> ( C = A \/ C = B ) ) ) |
| 5 |
|
orcom |
|- ( ( C = A \/ C = B ) <-> ( C = B \/ C = A ) ) |
| 6 |
|
nne |
|- ( -. B =/= C <-> B = C ) |
| 7 |
|
eqcom |
|- ( B = C <-> C = B ) |
| 8 |
6 7
|
bitr2i |
|- ( C = B <-> -. B =/= C ) |
| 9 |
|
nne |
|- ( -. C =/= A <-> C = A ) |
| 10 |
9
|
bicomi |
|- ( C = A <-> -. C =/= A ) |
| 11 |
8 10
|
orbi12i |
|- ( ( C = B \/ C = A ) <-> ( -. B =/= C \/ -. C =/= A ) ) |
| 12 |
5 11
|
bitri |
|- ( ( C = A \/ C = B ) <-> ( -. B =/= C \/ -. C =/= A ) ) |
| 13 |
4 12
|
bitrdi |
|- ( C e. W -> ( C e. { A , B } <-> ( -. B =/= C \/ -. C =/= A ) ) ) |
| 14 |
13
|
biimpd |
|- ( C e. W -> ( C e. { A , B } -> ( -. B =/= C \/ -. C =/= A ) ) ) |
| 15 |
14
|
3ad2ant3 |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( C e. { A , B } -> ( -. B =/= C \/ -. C =/= A ) ) ) |
| 16 |
15
|
imp |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ C e. { A , B } ) -> ( -. B =/= C \/ -. C =/= A ) ) |
| 17 |
16
|
olcd |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ C e. { A , B } ) -> ( -. A =/= B \/ ( -. B =/= C \/ -. C =/= A ) ) ) |
| 18 |
17
|
ex |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( C e. { A , B } -> ( -. A =/= B \/ ( -. B =/= C \/ -. C =/= A ) ) ) ) |
| 19 |
|
3orass |
|- ( ( -. A =/= B \/ -. B =/= C \/ -. C =/= A ) <-> ( -. A =/= B \/ ( -. B =/= C \/ -. C =/= A ) ) ) |
| 20 |
18 19
|
imbitrrdi |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( C e. { A , B } -> ( -. A =/= B \/ -. B =/= C \/ -. C =/= A ) ) ) |
| 21 |
|
3ianor |
|- ( -. ( A =/= B /\ B =/= C /\ C =/= A ) <-> ( -. A =/= B \/ -. B =/= C \/ -. C =/= A ) ) |
| 22 |
20 21
|
imbitrrdi |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( C e. { A , B } -> -. ( A =/= B /\ B =/= C /\ C =/= A ) ) ) |
| 23 |
22
|
con2d |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( A =/= B /\ B =/= C /\ C =/= A ) -> -. C e. { A , B } ) ) |
| 24 |
23
|
imp |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> -. C e. { A , B } ) |
| 25 |
|
hashunsng |
|- ( C e. W -> ( ( { A , B } e. Fin /\ -. C e. { A , B } ) -> ( # ` ( { A , B } u. { C } ) ) = ( ( # ` { A , B } ) + 1 ) ) ) |
| 26 |
25
|
imp |
|- ( ( C e. W /\ ( { A , B } e. Fin /\ -. C e. { A , B } ) ) -> ( # ` ( { A , B } u. { C } ) ) = ( ( # ` { A , B } ) + 1 ) ) |
| 27 |
1 3 24 26
|
syl12anc |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( # ` ( { A , B } u. { C } ) ) = ( ( # ` { A , B } ) + 1 ) ) |
| 28 |
|
simpr1 |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> A =/= B ) |
| 29 |
|
3simpa |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( A e. U /\ B e. V ) ) |
| 30 |
29
|
adantr |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( A e. U /\ B e. V ) ) |
| 31 |
|
hashprg |
|- ( ( A e. U /\ B e. V ) -> ( A =/= B <-> ( # ` { A , B } ) = 2 ) ) |
| 32 |
30 31
|
syl |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( A =/= B <-> ( # ` { A , B } ) = 2 ) ) |
| 33 |
28 32
|
mpbid |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( # ` { A , B } ) = 2 ) |
| 34 |
33
|
oveq1d |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( ( # ` { A , B } ) + 1 ) = ( 2 + 1 ) ) |
| 35 |
27 34
|
eqtrd |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( # ` ( { A , B } u. { C } ) ) = ( 2 + 1 ) ) |
| 36 |
|
df-tp |
|- { A , B , C } = ( { A , B } u. { C } ) |
| 37 |
36
|
fveq2i |
|- ( # ` { A , B , C } ) = ( # ` ( { A , B } u. { C } ) ) |
| 38 |
|
df-3 |
|- 3 = ( 2 + 1 ) |
| 39 |
35 37 38
|
3eqtr4g |
|- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( # ` { A , B , C } ) = 3 ) |
| 40 |
39
|
ex |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( A =/= B /\ B =/= C /\ C =/= A ) -> ( # ` { A , B , C } ) = 3 ) ) |
| 41 |
|
nne |
|- ( -. A =/= B <-> A = B ) |
| 42 |
|
hashprlei |
|- ( { B , C } e. Fin /\ ( # ` { B , C } ) <_ 2 ) |
| 43 |
|
prfi |
|- { B , C } e. Fin |
| 44 |
|
hashcl |
|- ( { B , C } e. Fin -> ( # ` { B , C } ) e. NN0 ) |
| 45 |
44
|
nn0zd |
|- ( { B , C } e. Fin -> ( # ` { B , C } ) e. ZZ ) |
| 46 |
43 45
|
ax-mp |
|- ( # ` { B , C } ) e. ZZ |
| 47 |
|
2z |
|- 2 e. ZZ |
| 48 |
|
zleltp1 |
|- ( ( ( # ` { B , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { B , C } ) <_ 2 <-> ( # ` { B , C } ) < ( 2 + 1 ) ) ) |
| 49 |
|
2p1e3 |
|- ( 2 + 1 ) = 3 |
| 50 |
49
|
a1i |
|- ( ( ( # ` { B , C } ) e. ZZ /\ 2 e. ZZ ) -> ( 2 + 1 ) = 3 ) |
| 51 |
50
|
breq2d |
|- ( ( ( # ` { B , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { B , C } ) < ( 2 + 1 ) <-> ( # ` { B , C } ) < 3 ) ) |
| 52 |
51
|
biimpd |
|- ( ( ( # ` { B , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { B , C } ) < ( 2 + 1 ) -> ( # ` { B , C } ) < 3 ) ) |
| 53 |
48 52
|
sylbid |
|- ( ( ( # ` { B , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { B , C } ) <_ 2 -> ( # ` { B , C } ) < 3 ) ) |
| 54 |
46 47 53
|
mp2an |
|- ( ( # ` { B , C } ) <_ 2 -> ( # ` { B , C } ) < 3 ) |
| 55 |
44
|
nn0red |
|- ( { B , C } e. Fin -> ( # ` { B , C } ) e. RR ) |
| 56 |
43 55
|
ax-mp |
|- ( # ` { B , C } ) e. RR |
| 57 |
|
3re |
|- 3 e. RR |
| 58 |
56 57
|
ltnei |
|- ( ( # ` { B , C } ) < 3 -> 3 =/= ( # ` { B , C } ) ) |
| 59 |
54 58
|
syl |
|- ( ( # ` { B , C } ) <_ 2 -> 3 =/= ( # ` { B , C } ) ) |
| 60 |
59
|
necomd |
|- ( ( # ` { B , C } ) <_ 2 -> ( # ` { B , C } ) =/= 3 ) |
| 61 |
60
|
adantl |
|- ( ( { B , C } e. Fin /\ ( # ` { B , C } ) <_ 2 ) -> ( # ` { B , C } ) =/= 3 ) |
| 62 |
42 61
|
mp1i |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { B , C } ) =/= 3 ) |
| 63 |
|
tpeq1 |
|- ( A = B -> { A , B , C } = { B , B , C } ) |
| 64 |
|
tpidm12 |
|- { B , B , C } = { B , C } |
| 65 |
63 64
|
eqtr2di |
|- ( A = B -> { B , C } = { A , B , C } ) |
| 66 |
65
|
fveq2d |
|- ( A = B -> ( # ` { B , C } ) = ( # ` { A , B , C } ) ) |
| 67 |
66
|
neeq1d |
|- ( A = B -> ( ( # ` { B , C } ) =/= 3 <-> ( # ` { A , B , C } ) =/= 3 ) ) |
| 68 |
62 67
|
imbitrid |
|- ( A = B -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 69 |
41 68
|
sylbi |
|- ( -. A =/= B -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 70 |
|
hashprlei |
|- ( { A , C } e. Fin /\ ( # ` { A , C } ) <_ 2 ) |
| 71 |
|
prfi |
|- { A , C } e. Fin |
| 72 |
|
hashcl |
|- ( { A , C } e. Fin -> ( # ` { A , C } ) e. NN0 ) |
| 73 |
72
|
nn0zd |
|- ( { A , C } e. Fin -> ( # ` { A , C } ) e. ZZ ) |
| 74 |
71 73
|
ax-mp |
|- ( # ` { A , C } ) e. ZZ |
| 75 |
|
zleltp1 |
|- ( ( ( # ` { A , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , C } ) <_ 2 <-> ( # ` { A , C } ) < ( 2 + 1 ) ) ) |
| 76 |
49
|
a1i |
|- ( ( ( # ` { A , C } ) e. ZZ /\ 2 e. ZZ ) -> ( 2 + 1 ) = 3 ) |
| 77 |
76
|
breq2d |
|- ( ( ( # ` { A , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , C } ) < ( 2 + 1 ) <-> ( # ` { A , C } ) < 3 ) ) |
| 78 |
77
|
biimpd |
|- ( ( ( # ` { A , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , C } ) < ( 2 + 1 ) -> ( # ` { A , C } ) < 3 ) ) |
| 79 |
75 78
|
sylbid |
|- ( ( ( # ` { A , C } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , C } ) <_ 2 -> ( # ` { A , C } ) < 3 ) ) |
| 80 |
74 47 79
|
mp2an |
|- ( ( # ` { A , C } ) <_ 2 -> ( # ` { A , C } ) < 3 ) |
| 81 |
72
|
nn0red |
|- ( { A , C } e. Fin -> ( # ` { A , C } ) e. RR ) |
| 82 |
71 81
|
ax-mp |
|- ( # ` { A , C } ) e. RR |
| 83 |
82 57
|
ltnei |
|- ( ( # ` { A , C } ) < 3 -> 3 =/= ( # ` { A , C } ) ) |
| 84 |
80 83
|
syl |
|- ( ( # ` { A , C } ) <_ 2 -> 3 =/= ( # ` { A , C } ) ) |
| 85 |
84
|
necomd |
|- ( ( # ` { A , C } ) <_ 2 -> ( # ` { A , C } ) =/= 3 ) |
| 86 |
85
|
adantl |
|- ( ( { A , C } e. Fin /\ ( # ` { A , C } ) <_ 2 ) -> ( # ` { A , C } ) =/= 3 ) |
| 87 |
70 86
|
mp1i |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , C } ) =/= 3 ) |
| 88 |
|
tpeq2 |
|- ( B = C -> { A , B , C } = { A , C , C } ) |
| 89 |
|
tpidm23 |
|- { A , C , C } = { A , C } |
| 90 |
88 89
|
eqtr2di |
|- ( B = C -> { A , C } = { A , B , C } ) |
| 91 |
90
|
fveq2d |
|- ( B = C -> ( # ` { A , C } ) = ( # ` { A , B , C } ) ) |
| 92 |
91
|
neeq1d |
|- ( B = C -> ( ( # ` { A , C } ) =/= 3 <-> ( # ` { A , B , C } ) =/= 3 ) ) |
| 93 |
87 92
|
imbitrid |
|- ( B = C -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 94 |
6 93
|
sylbi |
|- ( -. B =/= C -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 95 |
|
hashprlei |
|- ( { A , B } e. Fin /\ ( # ` { A , B } ) <_ 2 ) |
| 96 |
|
hashcl |
|- ( { A , B } e. Fin -> ( # ` { A , B } ) e. NN0 ) |
| 97 |
96
|
nn0zd |
|- ( { A , B } e. Fin -> ( # ` { A , B } ) e. ZZ ) |
| 98 |
2 97
|
ax-mp |
|- ( # ` { A , B } ) e. ZZ |
| 99 |
|
zleltp1 |
|- ( ( ( # ` { A , B } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , B } ) <_ 2 <-> ( # ` { A , B } ) < ( 2 + 1 ) ) ) |
| 100 |
49
|
a1i |
|- ( ( ( # ` { A , B } ) e. ZZ /\ 2 e. ZZ ) -> ( 2 + 1 ) = 3 ) |
| 101 |
100
|
breq2d |
|- ( ( ( # ` { A , B } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , B } ) < ( 2 + 1 ) <-> ( # ` { A , B } ) < 3 ) ) |
| 102 |
101
|
biimpd |
|- ( ( ( # ` { A , B } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , B } ) < ( 2 + 1 ) -> ( # ` { A , B } ) < 3 ) ) |
| 103 |
99 102
|
sylbid |
|- ( ( ( # ` { A , B } ) e. ZZ /\ 2 e. ZZ ) -> ( ( # ` { A , B } ) <_ 2 -> ( # ` { A , B } ) < 3 ) ) |
| 104 |
98 47 103
|
mp2an |
|- ( ( # ` { A , B } ) <_ 2 -> ( # ` { A , B } ) < 3 ) |
| 105 |
96
|
nn0red |
|- ( { A , B } e. Fin -> ( # ` { A , B } ) e. RR ) |
| 106 |
2 105
|
ax-mp |
|- ( # ` { A , B } ) e. RR |
| 107 |
106 57
|
ltnei |
|- ( ( # ` { A , B } ) < 3 -> 3 =/= ( # ` { A , B } ) ) |
| 108 |
104 107
|
syl |
|- ( ( # ` { A , B } ) <_ 2 -> 3 =/= ( # ` { A , B } ) ) |
| 109 |
108
|
necomd |
|- ( ( # ` { A , B } ) <_ 2 -> ( # ` { A , B } ) =/= 3 ) |
| 110 |
109
|
adantl |
|- ( ( { A , B } e. Fin /\ ( # ` { A , B } ) <_ 2 ) -> ( # ` { A , B } ) =/= 3 ) |
| 111 |
95 110
|
mp1i |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B } ) =/= 3 ) |
| 112 |
|
tpeq3 |
|- ( C = A -> { A , B , C } = { A , B , A } ) |
| 113 |
|
tpidm13 |
|- { A , B , A } = { A , B } |
| 114 |
112 113
|
eqtr2di |
|- ( C = A -> { A , B } = { A , B , C } ) |
| 115 |
114
|
fveq2d |
|- ( C = A -> ( # ` { A , B } ) = ( # ` { A , B , C } ) ) |
| 116 |
115
|
neeq1d |
|- ( C = A -> ( ( # ` { A , B } ) =/= 3 <-> ( # ` { A , B , C } ) =/= 3 ) ) |
| 117 |
111 116
|
imbitrid |
|- ( C = A -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 118 |
9 117
|
sylbi |
|- ( -. C =/= A -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 119 |
69 94 118
|
3jaoi |
|- ( ( -. A =/= B \/ -. B =/= C \/ -. C =/= A ) -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 120 |
21 119
|
sylbi |
|- ( -. ( A =/= B /\ B =/= C /\ C =/= A ) -> ( ( A e. U /\ B e. V /\ C e. W ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 121 |
120
|
com12 |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( -. ( A =/= B /\ B =/= C /\ C =/= A ) -> ( # ` { A , B , C } ) =/= 3 ) ) |
| 122 |
121
|
necon4bd |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( # ` { A , B , C } ) = 3 -> ( A =/= B /\ B =/= C /\ C =/= A ) ) ) |
| 123 |
40 122
|
impbid |
|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( A =/= B /\ B =/= C /\ C =/= A ) <-> ( # ` { A , B , C } ) = 3 ) ) |