Metamath Proof Explorer


Theorem musum

Description: The sum of the Möbius function over the divisors of N gives one if N = 1 , but otherwise always sums to zero. Theorem 2.1 in ApostolNT p. 25. This makes the Möbius function useful for inverting divisor sums; see also muinv . (Contributed by Mario Carneiro, 2-Jul-2015)

Ref Expression
Assertion musum N k n | n N μ k = if N = 1 1 0

Proof

Step Hyp Ref Expression
1 fveq2 n = k μ n = μ k
2 1 neeq1d n = k μ n 0 μ k 0
3 breq1 n = k n N k N
4 2 3 anbi12d n = k μ n 0 n N μ k 0 k N
5 4 elrab k n | μ n 0 n N k μ k 0 k N
6 muval2 k μ k 0 μ k = 1 p | p k
7 6 adantrr k μ k 0 k N μ k = 1 p | p k
8 5 7 sylbi k n | μ n 0 n N μ k = 1 p | p k
9 8 adantl N k n | μ n 0 n N μ k = 1 p | p k
10 9 sumeq2dv N k n | μ n 0 n N μ k = k n | μ n 0 n N 1 p | p k
11 simpr μ n 0 n N n N
12 11 a1i N n μ n 0 n N n N
13 12 ss2rabdv N n | μ n 0 n N n | n N
14 ssrab2 n | μ n 0 n N
15 simpr N k n | μ n 0 n N k n | μ n 0 n N
16 14 15 sselid N k n | μ n 0 n N k
17 mucl k μ k
18 16 17 syl N k n | μ n 0 n N μ k
19 18 zcnd N k n | μ n 0 n N μ k
20 difrab n | n N n | μ n 0 n N = n | n N ¬ μ n 0 n N
21 pm3.21 n N μ n 0 μ n 0 n N
22 21 necon1bd n N ¬ μ n 0 n N μ n = 0
23 22 imp n N ¬ μ n 0 n N μ n = 0
24 23 a1i n n N ¬ μ n 0 n N μ n = 0
25 24 ss2rabi n | n N ¬ μ n 0 n N n | μ n = 0
26 20 25 eqsstri n | n N n | μ n 0 n N n | μ n = 0
27 26 sseli k n | n N n | μ n 0 n N k n | μ n = 0
28 fveqeq2 n = k μ n = 0 μ k = 0
29 28 elrab k n | μ n = 0 k μ k = 0
30 29 simprbi k n | μ n = 0 μ k = 0
31 27 30 syl k n | n N n | μ n 0 n N μ k = 0
32 31 adantl N k n | n N n | μ n 0 n N μ k = 0
33 dvdsfi N n | n N Fin
34 13 19 32 33 fsumss N k n | μ n 0 n N μ k = k n | n N μ k
35 fveq2 x = p | p k x = p | p k
36 35 oveq2d x = p | p k 1 x = 1 p | p k
37 33 13 ssfid N n | μ n 0 n N Fin
38 eqid n | μ n 0 n N = n | μ n 0 n N
39 eqid m n | μ n 0 n N p | p m = m n | μ n 0 n N p | p m
40 oveq1 q = p q pCnt x = p pCnt x
41 40 cbvmptv q q pCnt x = p p pCnt x
42 oveq2 x = m p pCnt x = p pCnt m
43 42 mpteq2dv x = m p p pCnt x = p p pCnt m
44 41 43 eqtrid x = m q q pCnt x = p p pCnt m
45 44 cbvmptv x q q pCnt x = m p p pCnt m
46 38 39 45 sqff1o N m n | μ n 0 n N p | p m : n | μ n 0 n N 1-1 onto 𝒫 p | p N
47 breq2 m = k p m p k
48 47 rabbidv m = k p | p m = p | p k
49 prmex V
50 49 rabex p | p k V
51 48 39 50 fvmpt k n | μ n 0 n N m n | μ n 0 n N p | p m k = p | p k
52 51 adantl N k n | μ n 0 n N m n | μ n 0 n N p | p m k = p | p k
53 neg1cn 1
54 prmdvdsfi N p | p N Fin
55 elpwi x 𝒫 p | p N x p | p N
56 ssfi p | p N Fin x p | p N x Fin
57 54 55 56 syl2an N x 𝒫 p | p N x Fin
58 hashcl x Fin x 0
59 57 58 syl N x 𝒫 p | p N x 0
60 expcl 1 x 0 1 x
61 53 59 60 sylancr N x 𝒫 p | p N 1 x
62 36 37 46 52 61 fsumf1o N x 𝒫 p | p N 1 x = k n | μ n 0 n N 1 p | p k
63 fzfid N 0 p | p N Fin
64 54 adantr N z 0 p | p N p | p N Fin
65 pwfi p | p N Fin 𝒫 p | p N Fin
66 64 65 sylib N z 0 p | p N 𝒫 p | p N Fin
67 ssrab2 s 𝒫 p | p N | s = z 𝒫 p | p N
68 ssfi 𝒫 p | p N Fin s 𝒫 p | p N | s = z 𝒫 p | p N s 𝒫 p | p N | s = z Fin
69 66 67 68 sylancl N z 0 p | p N s 𝒫 p | p N | s = z Fin
70 simprr N z 0 p | p N x s 𝒫 p | p N | s = z x s 𝒫 p | p N | s = z
71 fveqeq2 s = x s = z x = z
72 71 elrab x s 𝒫 p | p N | s = z x 𝒫 p | p N x = z
73 72 simprbi x s 𝒫 p | p N | s = z x = z
74 70 73 syl N z 0 p | p N x s 𝒫 p | p N | s = z x = z
75 74 ralrimivva N z 0 p | p N x s 𝒫 p | p N | s = z x = z
76 invdisj z 0 p | p N x s 𝒫 p | p N | s = z x = z Disj z = 0 p | p N s 𝒫 p | p N | s = z
77 75 76 syl N Disj z = 0 p | p N s 𝒫 p | p N | s = z
78 54 adantr N z 0 p | p N x s 𝒫 p | p N | s = z p | p N Fin
79 67 70 sselid N z 0 p | p N x s 𝒫 p | p N | s = z x 𝒫 p | p N
80 79 55 syl N z 0 p | p N x s 𝒫 p | p N | s = z x p | p N
81 78 80 ssfid N z 0 p | p N x s 𝒫 p | p N | s = z x Fin
82 81 58 syl N z 0 p | p N x s 𝒫 p | p N | s = z x 0
83 53 82 60 sylancr N z 0 p | p N x s 𝒫 p | p N | s = z 1 x
84 63 69 77 83 fsumiun N x z = 0 p | p N s 𝒫 p | p N | s = z 1 x = z = 0 p | p N x s 𝒫 p | p N | s = z 1 x
85 iunrab z = 0 p | p N s 𝒫 p | p N | s = z = s 𝒫 p | p N | z 0 p | p N s = z
86 54 adantr N s 𝒫 p | p N p | p N Fin
87 elpwi s 𝒫 p | p N s p | p N
88 87 adantl N s 𝒫 p | p N s p | p N
89 ssdomg p | p N Fin s p | p N s p | p N
90 86 88 89 sylc N s 𝒫 p | p N s p | p N
91 ssfi p | p N Fin s p | p N s Fin
92 54 87 91 syl2an N s 𝒫 p | p N s Fin
93 hashdom s Fin p | p N Fin s p | p N s p | p N
94 92 86 93 syl2anc N s 𝒫 p | p N s p | p N s p | p N
95 90 94 mpbird N s 𝒫 p | p N s p | p N
96 hashcl s Fin s 0
97 92 96 syl N s 𝒫 p | p N s 0
98 nn0uz 0 = 0
99 97 98 eleqtrdi N s 𝒫 p | p N s 0
100 hashcl p | p N Fin p | p N 0
101 54 100 syl N p | p N 0
102 101 adantr N s 𝒫 p | p N p | p N 0
103 102 nn0zd N s 𝒫 p | p N p | p N
104 elfz5 s 0 p | p N s 0 p | p N s p | p N
105 99 103 104 syl2anc N s 𝒫 p | p N s 0 p | p N s p | p N
106 95 105 mpbird N s 𝒫 p | p N s 0 p | p N
107 eqidd N s 𝒫 p | p N s = s
108 eqeq2 z = s s = z s = s
109 108 rspcev s 0 p | p N s = s z 0 p | p N s = z
110 106 107 109 syl2anc N s 𝒫 p | p N z 0 p | p N s = z
111 110 ralrimiva N s 𝒫 p | p N z 0 p | p N s = z
112 rabid2 𝒫 p | p N = s 𝒫 p | p N | z 0 p | p N s = z s 𝒫 p | p N z 0 p | p N s = z
113 111 112 sylibr N 𝒫 p | p N = s 𝒫 p | p N | z 0 p | p N s = z
114 85 113 eqtr4id N z = 0 p | p N s 𝒫 p | p N | s = z = 𝒫 p | p N
115 114 sumeq1d N x z = 0 p | p N s 𝒫 p | p N | s = z 1 x = x 𝒫 p | p N 1 x
116 elfznn0 z 0 p | p N z 0
117 116 adantl N z 0 p | p N z 0
118 expcl 1 z 0 1 z
119 53 117 118 sylancr N z 0 p | p N 1 z
120 fsumconst s 𝒫 p | p N | s = z Fin 1 z x s 𝒫 p | p N | s = z 1 z = s 𝒫 p | p N | s = z 1 z
121 69 119 120 syl2anc N z 0 p | p N x s 𝒫 p | p N | s = z 1 z = s 𝒫 p | p N | s = z 1 z
122 73 adantl N z 0 p | p N x s 𝒫 p | p N | s = z x = z
123 122 oveq2d N z 0 p | p N x s 𝒫 p | p N | s = z 1 x = 1 z
124 123 sumeq2dv N z 0 p | p N x s 𝒫 p | p N | s = z 1 x = x s 𝒫 p | p N | s = z 1 z
125 elfzelz z 0 p | p N z
126 hashbc p | p N Fin z ( p | p N z) = s 𝒫 p | p N | s = z
127 54 125 126 syl2an N z 0 p | p N ( p | p N z) = s 𝒫 p | p N | s = z
128 127 oveq1d N z 0 p | p N ( p | p N z) 1 z = s 𝒫 p | p N | s = z 1 z
129 121 124 128 3eqtr4d N z 0 p | p N x s 𝒫 p | p N | s = z 1 x = ( p | p N z) 1 z
130 129 sumeq2dv N z = 0 p | p N x s 𝒫 p | p N | s = z 1 x = z = 0 p | p N ( p | p N z) 1 z
131 1pneg1e0 1 + -1 = 0
132 131 oveq1i 1 + -1 p | p N = 0 p | p N
133 binom1p 1 p | p N 0 1 + -1 p | p N = z = 0 p | p N ( p | p N z) 1 z
134 53 101 133 sylancr N 1 + -1 p | p N = z = 0 p | p N ( p | p N z) 1 z
135 132 134 eqtr3id N 0 p | p N = z = 0 p | p N ( p | p N z) 1 z
136 eqeq2 1 = if N = 1 1 0 0 p | p N = 1 0 p | p N = if N = 1 1 0
137 eqeq2 0 = if N = 1 1 0 0 p | p N = 0 0 p | p N = if N = 1 1 0
138 nprmdvds1 p ¬ p 1
139 simpr N N = 1 N = 1
140 139 breq2d N N = 1 p N p 1
141 140 notbid N N = 1 ¬ p N ¬ p 1
142 138 141 imbitrrid N N = 1 p ¬ p N
143 142 ralrimiv N N = 1 p ¬ p N
144 rabeq0 p | p N = p ¬ p N
145 143 144 sylibr N N = 1 p | p N =
146 145 fveq2d N N = 1 p | p N =
147 hash0 = 0
148 146 147 eqtrdi N N = 1 p | p N = 0
149 148 oveq2d N N = 1 0 p | p N = 0 0
150 0exp0e1 0 0 = 1
151 149 150 eqtrdi N N = 1 0 p | p N = 1
152 df-ne N 1 ¬ N = 1
153 eluz2b3 N 2 N N 1
154 153 biimpri N N 1 N 2
155 152 154 sylan2br N ¬ N = 1 N 2
156 exprmfct N 2 p p N
157 155 156 syl N ¬ N = 1 p p N
158 rabn0 p | p N p p N
159 157 158 sylibr N ¬ N = 1 p | p N
160 54 adantr N ¬ N = 1 p | p N Fin
161 hashnncl p | p N Fin p | p N p | p N
162 160 161 syl N ¬ N = 1 p | p N p | p N
163 159 162 mpbird N ¬ N = 1 p | p N
164 163 0expd N ¬ N = 1 0 p | p N = 0
165 136 137 151 164 ifbothda N 0 p | p N = if N = 1 1 0
166 130 135 165 3eqtr2d N z = 0 p | p N x s 𝒫 p | p N | s = z 1 x = if N = 1 1 0
167 84 115 166 3eqtr3d N x 𝒫 p | p N 1 x = if N = 1 1 0
168 62 167 eqtr3d N k n | μ n 0 n N 1 p | p k = if N = 1 1 0
169 10 34 168 3eqtr3d N k n | n N μ k = if N = 1 1 0