Metamath Proof Explorer


Theorem odzval

Description: Value of the order function. This is a function of functions; the inner argument selects the base (i.e., mod N for some N , often prime) and the outer argument selects the integer or equivalence class (if you want to think about it that way) from the integers mod N . In order to ensure the supremum is well-defined, we only define the expression when A and N are coprime. (Contributed by Mario Carneiro, 23-Feb-2014) (Revised by AV, 26-Sep-2020)

Ref Expression
Assertion odzval NAAgcdN=1odNA=supn|NAn1<

Proof

Step Hyp Ref Expression
1 oveq2 m=Nxgcdm=xgcdN
2 1 eqeq1d m=Nxgcdm=1xgcdN=1
3 2 rabbidv m=Nx|xgcdm=1=x|xgcdN=1
4 oveq1 n=xngcdN=xgcdN
5 4 eqeq1d n=xngcdN=1xgcdN=1
6 5 cbvrabv n|ngcdN=1=x|xgcdN=1
7 3 6 eqtr4di m=Nx|xgcdm=1=n|ngcdN=1
8 breq1 m=Nmxn1Nxn1
9 8 rabbidv m=Nn|mxn1=n|Nxn1
10 9 infeq1d m=Nsupn|mxn1<=supn|Nxn1<
11 7 10 mpteq12dv m=Nxx|xgcdm=1supn|mxn1<=xn|ngcdN=1supn|Nxn1<
12 df-odz od=mxx|xgcdm=1supn|mxn1<
13 zex V
14 13 mptrabex xn|ngcdN=1supn|Nxn1<V
15 11 12 14 fvmpt NodN=xn|ngcdN=1supn|Nxn1<
16 15 fveq1d NodNA=xn|ngcdN=1supn|Nxn1<A
17 oveq1 n=AngcdN=AgcdN
18 17 eqeq1d n=AngcdN=1AgcdN=1
19 18 elrab An|ngcdN=1AAgcdN=1
20 oveq1 x=Axn=An
21 20 oveq1d x=Axn1=An1
22 21 breq2d x=ANxn1NAn1
23 22 rabbidv x=An|Nxn1=n|NAn1
24 23 infeq1d x=Asupn|Nxn1<=supn|NAn1<
25 eqid xn|ngcdN=1supn|Nxn1<=xn|ngcdN=1supn|Nxn1<
26 ltso <Or
27 26 infex supn|NAn1<V
28 24 25 27 fvmpt An|ngcdN=1xn|ngcdN=1supn|Nxn1<A=supn|NAn1<
29 19 28 sylbir AAgcdN=1xn|ngcdN=1supn|Nxn1<A=supn|NAn1<
30 16 29 sylan9eq NAAgcdN=1odNA=supn|NAn1<
31 30 3impb NAAgcdN=1odNA=supn|NAn1<