Metamath Proof Explorer


Theorem 1lgs

Description: The Legendre symbol at 1 . See example 1 in ApostolNT p. 180. (Contributed by Mario Carneiro, 28-Apr-2016)

Ref Expression
Assertion 1lgs N1/LN=1

Proof

Step Hyp Ref Expression
1 sq1 12=1
2 1 oveq1i 12/LN=1/LN
3 1gcd N1gcdN=1
4 1z 1
5 ax-1ne0 10
6 4 5 pm3.2i 110
7 lgssq 110N1gcdN=112/LN=1
8 6 7 mp3an1 N1gcdN=112/LN=1
9 3 8 mpdan N12/LN=1
10 2 9 eqtr3id N1/LN=1