Metamath Proof Explorer


Theorem gausslemma2dlem0e

Description: Auxiliary lemma 5 for gausslemma2d . (Contributed by AV, 9-Jul-2021)

Ref Expression
Hypotheses gausslemma2dlem0.p
|- ( ph -> P e. ( Prime \ { 2 } ) )
gausslemma2dlem0.m
|- M = ( |_ ` ( P / 4 ) )
Assertion gausslemma2dlem0e
|- ( ph -> ( M x. 2 ) < ( P / 2 ) )

Proof

Step Hyp Ref Expression
1 gausslemma2dlem0.p
 |-  ( ph -> P e. ( Prime \ { 2 } ) )
2 gausslemma2dlem0.m
 |-  M = ( |_ ` ( P / 4 ) )
3 2 oveq1i
 |-  ( M x. 2 ) = ( ( |_ ` ( P / 4 ) ) x. 2 )
4 nnoddn2prm
 |-  ( P e. ( Prime \ { 2 } ) -> ( P e. NN /\ -. 2 || P ) )
5 nnz
 |-  ( P e. NN -> P e. ZZ )
6 5 anim1i
 |-  ( ( P e. NN /\ -. 2 || P ) -> ( P e. ZZ /\ -. 2 || P ) )
7 1 4 6 3syl
 |-  ( ph -> ( P e. ZZ /\ -. 2 || P ) )
8 flodddiv4t2lthalf
 |-  ( ( P e. ZZ /\ -. 2 || P ) -> ( ( |_ ` ( P / 4 ) ) x. 2 ) < ( P / 2 ) )
9 7 8 syl
 |-  ( ph -> ( ( |_ ` ( P / 4 ) ) x. 2 ) < ( P / 2 ) )
10 3 9 eqbrtrid
 |-  ( ph -> ( M x. 2 ) < ( P / 2 ) )