| Step |
Hyp |
Ref |
Expression |
| 1 |
|
gpgusgralem.j |
|- J = ( 1 ..^ ( |^ ` ( N / 2 ) ) ) |
| 2 |
|
gpgusgralem.i |
|- I = ( 0 ..^ N ) |
| 3 |
|
uzuzle23 |
|- ( N e. ( ZZ>= ` 3 ) -> N e. ( ZZ>= ` 2 ) ) |
| 4 |
3
|
adantr |
|- ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) -> N e. ( ZZ>= ` 2 ) ) |
| 5 |
4
|
adantr |
|- ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) -> N e. ( ZZ>= ` 2 ) ) |
| 6 |
2
|
eleq2i |
|- ( x e. I <-> x e. ( 0 ..^ N ) ) |
| 7 |
6
|
biimpi |
|- ( x e. I -> x e. ( 0 ..^ N ) ) |
| 8 |
|
p1modne |
|- ( ( N e. ( ZZ>= ` 2 ) /\ x e. ( 0 ..^ N ) ) -> ( ( x + 1 ) mod N ) =/= x ) |
| 9 |
5 7 8
|
syl2an |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( ( x + 1 ) mod N ) =/= x ) |
| 10 |
9
|
necomd |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> x =/= ( ( x + 1 ) mod N ) ) |
| 11 |
10
|
olcd |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( 0 =/= 0 \/ x =/= ( ( x + 1 ) mod N ) ) ) |
| 12 |
|
0z |
|- 0 e. ZZ |
| 13 |
|
vex |
|- x e. _V |
| 14 |
|
opthneg |
|- ( ( 0 e. ZZ /\ x e. _V ) -> ( <. 0 , x >. =/= <. 0 , ( ( x + 1 ) mod N ) >. <-> ( 0 =/= 0 \/ x =/= ( ( x + 1 ) mod N ) ) ) ) |
| 15 |
12 13 14
|
mp2an |
|- ( <. 0 , x >. =/= <. 0 , ( ( x + 1 ) mod N ) >. <-> ( 0 =/= 0 \/ x =/= ( ( x + 1 ) mod N ) ) ) |
| 16 |
11 15
|
sylibr |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> <. 0 , x >. =/= <. 0 , ( ( x + 1 ) mod N ) >. ) |
| 17 |
|
opex |
|- <. 0 , x >. e. _V |
| 18 |
|
opex |
|- <. 0 , ( ( x + 1 ) mod N ) >. e. _V |
| 19 |
|
hashprg |
|- ( ( <. 0 , x >. e. _V /\ <. 0 , ( ( x + 1 ) mod N ) >. e. _V ) -> ( <. 0 , x >. =/= <. 0 , ( ( x + 1 ) mod N ) >. <-> ( # ` { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } ) = 2 ) ) |
| 20 |
17 18 19
|
mp2an |
|- ( <. 0 , x >. =/= <. 0 , ( ( x + 1 ) mod N ) >. <-> ( # ` { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } ) = 2 ) |
| 21 |
16 20
|
sylib |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( # ` { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } ) = 2 ) |
| 22 |
|
fveqeq2 |
|- ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } -> ( ( # ` e ) = 2 <-> ( # ` { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } ) = 2 ) ) |
| 23 |
21 22
|
syl5ibrcom |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } -> ( # ` e ) = 2 ) ) |
| 24 |
|
0ne1 |
|- 0 =/= 1 |
| 25 |
24
|
a1i |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> 0 =/= 1 ) |
| 26 |
25
|
orcd |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> ( 0 =/= 1 \/ x =/= x ) ) |
| 27 |
|
opthneg |
|- ( ( 0 e. ZZ /\ x e. _V ) -> ( <. 0 , x >. =/= <. 1 , x >. <-> ( 0 =/= 1 \/ x =/= x ) ) ) |
| 28 |
12 13 27
|
mp2an |
|- ( <. 0 , x >. =/= <. 1 , x >. <-> ( 0 =/= 1 \/ x =/= x ) ) |
| 29 |
26 28
|
sylibr |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> <. 0 , x >. =/= <. 1 , x >. ) |
| 30 |
|
opex |
|- <. 1 , x >. e. _V |
| 31 |
|
hashprg |
|- ( ( <. 0 , x >. e. _V /\ <. 1 , x >. e. _V ) -> ( <. 0 , x >. =/= <. 1 , x >. <-> ( # ` { <. 0 , x >. , <. 1 , x >. } ) = 2 ) ) |
| 32 |
17 30 31
|
mp2an |
|- ( <. 0 , x >. =/= <. 1 , x >. <-> ( # ` { <. 0 , x >. , <. 1 , x >. } ) = 2 ) |
| 33 |
29 32
|
sylib |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> ( # ` { <. 0 , x >. , <. 1 , x >. } ) = 2 ) |
| 34 |
|
fveqeq2 |
|- ( e = { <. 0 , x >. , <. 1 , x >. } -> ( ( # ` e ) = 2 <-> ( # ` { <. 0 , x >. , <. 1 , x >. } ) = 2 ) ) |
| 35 |
34
|
adantl |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> ( ( # ` e ) = 2 <-> ( # ` { <. 0 , x >. , <. 1 , x >. } ) = 2 ) ) |
| 36 |
33 35
|
mpbird |
|- ( ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) /\ e = { <. 0 , x >. , <. 1 , x >. } ) -> ( # ` e ) = 2 ) |
| 37 |
36
|
ex |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( e = { <. 0 , x >. , <. 1 , x >. } -> ( # ` e ) = 2 ) ) |
| 38 |
|
eluzge3nn |
|- ( N e. ( ZZ>= ` 3 ) -> N e. NN ) |
| 39 |
38
|
ad3antrrr |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> N e. NN ) |
| 40 |
|
elfzo0 |
|- ( x e. ( 0 ..^ N ) <-> ( x e. NN0 /\ N e. NN /\ x < N ) ) |
| 41 |
6 40
|
bitri |
|- ( x e. I <-> ( x e. NN0 /\ N e. NN /\ x < N ) ) |
| 42 |
|
3simpb |
|- ( ( x e. NN0 /\ N e. NN /\ x < N ) -> ( x e. NN0 /\ x < N ) ) |
| 43 |
41 42
|
sylbi |
|- ( x e. I -> ( x e. NN0 /\ x < N ) ) |
| 44 |
43
|
adantl |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( x e. NN0 /\ x < N ) ) |
| 45 |
1
|
eleq2i |
|- ( K e. J <-> K e. ( 1 ..^ ( |^ ` ( N / 2 ) ) ) ) |
| 46 |
|
elfzo1 |
|- ( K e. ( 1 ..^ ( |^ ` ( N / 2 ) ) ) <-> ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) ) |
| 47 |
45 46
|
bitri |
|- ( K e. J <-> ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) ) |
| 48 |
|
simpl1 |
|- ( ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) /\ N e. ( ZZ>= ` 3 ) ) -> K e. NN ) |
| 49 |
|
nnre |
|- ( K e. NN -> K e. RR ) |
| 50 |
|
nnre |
|- ( ( |^ ` ( N / 2 ) ) e. NN -> ( |^ ` ( N / 2 ) ) e. RR ) |
| 51 |
|
eluzelre |
|- ( N e. ( ZZ>= ` 3 ) -> N e. RR ) |
| 52 |
49 50 51
|
3anim123i |
|- ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( K e. RR /\ ( |^ ` ( N / 2 ) ) e. RR /\ N e. RR ) ) |
| 53 |
51
|
rehalfcld |
|- ( N e. ( ZZ>= ` 3 ) -> ( N / 2 ) e. RR ) |
| 54 |
53
|
adantl |
|- ( ( K e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( N / 2 ) e. RR ) |
| 55 |
|
eluzelz |
|- ( N e. ( ZZ>= ` 3 ) -> N e. ZZ ) |
| 56 |
55
|
adantl |
|- ( ( K e. NN /\ N e. ( ZZ>= ` 3 ) ) -> N e. ZZ ) |
| 57 |
|
eluz2 |
|- ( N e. ( ZZ>= ` 3 ) <-> ( 3 e. ZZ /\ N e. ZZ /\ 3 <_ N ) ) |
| 58 |
|
simp2 |
|- ( ( 3 e. ZZ /\ N e. ZZ /\ 3 <_ N ) -> N e. ZZ ) |
| 59 |
|
0re |
|- 0 e. RR |
| 60 |
59
|
a1i |
|- ( ( N e. ZZ /\ 3 <_ N ) -> 0 e. RR ) |
| 61 |
|
3re |
|- 3 e. RR |
| 62 |
61
|
a1i |
|- ( ( N e. ZZ /\ 3 <_ N ) -> 3 e. RR ) |
| 63 |
|
zre |
|- ( N e. ZZ -> N e. RR ) |
| 64 |
63
|
adantr |
|- ( ( N e. ZZ /\ 3 <_ N ) -> N e. RR ) |
| 65 |
|
3pos |
|- 0 < 3 |
| 66 |
59 61 65
|
ltleii |
|- 0 <_ 3 |
| 67 |
66
|
a1i |
|- ( ( N e. ZZ /\ 3 <_ N ) -> 0 <_ 3 ) |
| 68 |
|
simpr |
|- ( ( N e. ZZ /\ 3 <_ N ) -> 3 <_ N ) |
| 69 |
60 62 64 67 68
|
letrd |
|- ( ( N e. ZZ /\ 3 <_ N ) -> 0 <_ N ) |
| 70 |
69
|
3adant1 |
|- ( ( 3 e. ZZ /\ N e. ZZ /\ 3 <_ N ) -> 0 <_ N ) |
| 71 |
58 70
|
jca |
|- ( ( 3 e. ZZ /\ N e. ZZ /\ 3 <_ N ) -> ( N e. ZZ /\ 0 <_ N ) ) |
| 72 |
|
elnn0z |
|- ( N e. NN0 <-> ( N e. ZZ /\ 0 <_ N ) ) |
| 73 |
71 72
|
sylibr |
|- ( ( 3 e. ZZ /\ N e. ZZ /\ 3 <_ N ) -> N e. NN0 ) |
| 74 |
57 73
|
sylbi |
|- ( N e. ( ZZ>= ` 3 ) -> N e. NN0 ) |
| 75 |
|
2nn |
|- 2 e. NN |
| 76 |
75
|
a1i |
|- ( ( K e. NN /\ N e. ( ZZ>= ` 3 ) ) -> 2 e. NN ) |
| 77 |
|
nn0ledivnn |
|- ( ( N e. NN0 /\ 2 e. NN ) -> ( N / 2 ) <_ N ) |
| 78 |
74 76 77
|
syl2an2 |
|- ( ( K e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( N / 2 ) <_ N ) |
| 79 |
54 56 78
|
3jca |
|- ( ( K e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( ( N / 2 ) e. RR /\ N e. ZZ /\ ( N / 2 ) <_ N ) ) |
| 80 |
79
|
3adant2 |
|- ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( ( N / 2 ) e. RR /\ N e. ZZ /\ ( N / 2 ) <_ N ) ) |
| 81 |
|
ceille |
|- ( ( ( N / 2 ) e. RR /\ N e. ZZ /\ ( N / 2 ) <_ N ) -> ( |^ ` ( N / 2 ) ) <_ N ) |
| 82 |
80 81
|
syl |
|- ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( |^ ` ( N / 2 ) ) <_ N ) |
| 83 |
52 82
|
lelttrdi |
|- ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ N e. ( ZZ>= ` 3 ) ) -> ( K < ( |^ ` ( N / 2 ) ) -> K < N ) ) |
| 84 |
83
|
3exp |
|- ( K e. NN -> ( ( |^ ` ( N / 2 ) ) e. NN -> ( N e. ( ZZ>= ` 3 ) -> ( K < ( |^ ` ( N / 2 ) ) -> K < N ) ) ) ) |
| 85 |
84
|
com34 |
|- ( K e. NN -> ( ( |^ ` ( N / 2 ) ) e. NN -> ( K < ( |^ ` ( N / 2 ) ) -> ( N e. ( ZZ>= ` 3 ) -> K < N ) ) ) ) |
| 86 |
85
|
3imp1 |
|- ( ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) /\ N e. ( ZZ>= ` 3 ) ) -> K < N ) |
| 87 |
48 86
|
jca |
|- ( ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) /\ N e. ( ZZ>= ` 3 ) ) -> ( K e. NN /\ K < N ) ) |
| 88 |
87
|
ex |
|- ( ( K e. NN /\ ( |^ ` ( N / 2 ) ) e. NN /\ K < ( |^ ` ( N / 2 ) ) ) -> ( N e. ( ZZ>= ` 3 ) -> ( K e. NN /\ K < N ) ) ) |
| 89 |
47 88
|
sylbi |
|- ( K e. J -> ( N e. ( ZZ>= ` 3 ) -> ( K e. NN /\ K < N ) ) ) |
| 90 |
89
|
impcom |
|- ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) -> ( K e. NN /\ K < N ) ) |
| 91 |
90
|
adantr |
|- ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) -> ( K e. NN /\ K < N ) ) |
| 92 |
91
|
adantr |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( K e. NN /\ K < N ) ) |
| 93 |
|
addmodne |
|- ( ( N e. NN /\ ( x e. NN0 /\ x < N ) /\ ( K e. NN /\ K < N ) ) -> ( ( x + K ) mod N ) =/= x ) |
| 94 |
39 44 92 93
|
syl3anc |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( ( x + K ) mod N ) =/= x ) |
| 95 |
94
|
necomd |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> x =/= ( ( x + K ) mod N ) ) |
| 96 |
95
|
olcd |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( 1 =/= 1 \/ x =/= ( ( x + K ) mod N ) ) ) |
| 97 |
|
1z |
|- 1 e. ZZ |
| 98 |
|
opthneg |
|- ( ( 1 e. ZZ /\ x e. _V ) -> ( <. 1 , x >. =/= <. 1 , ( ( x + K ) mod N ) >. <-> ( 1 =/= 1 \/ x =/= ( ( x + K ) mod N ) ) ) ) |
| 99 |
97 13 98
|
mp2an |
|- ( <. 1 , x >. =/= <. 1 , ( ( x + K ) mod N ) >. <-> ( 1 =/= 1 \/ x =/= ( ( x + K ) mod N ) ) ) |
| 100 |
96 99
|
sylibr |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> <. 1 , x >. =/= <. 1 , ( ( x + K ) mod N ) >. ) |
| 101 |
|
opex |
|- <. 1 , ( ( x + K ) mod N ) >. e. _V |
| 102 |
|
hashprg |
|- ( ( <. 1 , x >. e. _V /\ <. 1 , ( ( x + K ) mod N ) >. e. _V ) -> ( <. 1 , x >. =/= <. 1 , ( ( x + K ) mod N ) >. <-> ( # ` { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) = 2 ) ) |
| 103 |
30 101 102
|
mp2an |
|- ( <. 1 , x >. =/= <. 1 , ( ( x + K ) mod N ) >. <-> ( # ` { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) = 2 ) |
| 104 |
100 103
|
sylib |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( # ` { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) = 2 ) |
| 105 |
|
fveqeq2 |
|- ( e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } -> ( ( # ` e ) = 2 <-> ( # ` { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) = 2 ) ) |
| 106 |
104 105
|
syl5ibrcom |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } -> ( # ` e ) = 2 ) ) |
| 107 |
23 37 106
|
3jaod |
|- ( ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) /\ x e. I ) -> ( ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } \/ e = { <. 0 , x >. , <. 1 , x >. } \/ e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) -> ( # ` e ) = 2 ) ) |
| 108 |
107
|
rexlimdva |
|- ( ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) /\ e e. ~P ( { 0 , 1 } X. I ) ) -> ( E. x e. I ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } \/ e = { <. 0 , x >. , <. 1 , x >. } \/ e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) -> ( # ` e ) = 2 ) ) |
| 109 |
108
|
ss2rabdv |
|- ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) -> { e e. ~P ( { 0 , 1 } X. I ) | E. x e. I ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } \/ e = { <. 0 , x >. , <. 1 , x >. } \/ e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) } C_ { e e. ~P ( { 0 , 1 } X. I ) | ( # ` e ) = 2 } ) |
| 110 |
|
fveqeq2 |
|- ( p = e -> ( ( # ` p ) = 2 <-> ( # ` e ) = 2 ) ) |
| 111 |
110
|
cbvrabv |
|- { p e. ~P ( { 0 , 1 } X. I ) | ( # ` p ) = 2 } = { e e. ~P ( { 0 , 1 } X. I ) | ( # ` e ) = 2 } |
| 112 |
109 111
|
sseqtrrdi |
|- ( ( N e. ( ZZ>= ` 3 ) /\ K e. J ) -> { e e. ~P ( { 0 , 1 } X. I ) | E. x e. I ( e = { <. 0 , x >. , <. 0 , ( ( x + 1 ) mod N ) >. } \/ e = { <. 0 , x >. , <. 1 , x >. } \/ e = { <. 1 , x >. , <. 1 , ( ( x + K ) mod N ) >. } ) } C_ { p e. ~P ( { 0 , 1 } X. I ) | ( # ` p ) = 2 } ) |