Metamath Proof Explorer


Definition df-pellfund

Description: A function mapping Pell discriminants to the corresponding fundamental solution. (Contributed by Stefan O'Rear, 18-Sep-2014) (Revised by AV, 17-Sep-2020)

Ref Expression
Assertion df-pellfund
|- PellFund = ( x e. ( NN \ []NN ) |-> inf ( { z e. ( Pell14QR ` x ) | 1 < z } , RR , < ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cpellfund
 |-  PellFund
1 vx
 |-  x
2 cn
 |-  NN
3 csquarenn
 |-  []NN
4 2 3 cdif
 |-  ( NN \ []NN )
5 vz
 |-  z
6 cpell14qr
 |-  Pell14QR
7 1 cv
 |-  x
8 7 6 cfv
 |-  ( Pell14QR ` x )
9 c1
 |-  1
10 clt
 |-  <
11 5 cv
 |-  z
12 9 11 10 wbr
 |-  1 < z
13 12 5 8 crab
 |-  { z e. ( Pell14QR ` x ) | 1 < z }
14 cr
 |-  RR
15 13 14 10 cinf
 |-  inf ( { z e. ( Pell14QR ` x ) | 1 < z } , RR , < )
16 1 4 15 cmpt
 |-  ( x e. ( NN \ []NN ) |-> inf ( { z e. ( Pell14QR ` x ) | 1 < z } , RR , < ) )
17 0 16 wceq
 |-  PellFund = ( x e. ( NN \ []NN ) |-> inf ( { z e. ( Pell14QR ` x ) | 1 < z } , RR , < ) )