Metamath Proof Explorer


Theorem 2lgslem3d1

Description: Lemma 4 for 2lgslem3 . (Contributed by AV, 15-Jul-2021)

Ref Expression
Hypothesis 2lgslem2.n N=P12P4
Assertion 2lgslem3d1 PPmod8=7Nmod2=0

Proof

Step Hyp Ref Expression
1 2lgslem2.n N=P12P4
2 nnnn0 PP0
3 8nn 8
4 nnrp 88+
5 3 4 ax-mp 8+
6 modmuladdnn0 P08+Pmod8=7k0P=k8+7
7 2 5 6 sylancl PPmod8=7k0P=k8+7
8 simpr Pk0k0
9 nn0cn k0k
10 8cn 8
11 10 a1i k08
12 9 11 mulcomd k0k8=8k
13 12 adantl Pk0k8=8k
14 13 oveq1d Pk0k8+7=8k+7
15 14 eqeq2d Pk0P=k8+7P=8k+7
16 15 biimpa Pk0P=k8+7P=8k+7
17 1 2lgslem3d k0P=8k+7N=2k+2
18 8 16 17 syl2an2r Pk0P=k8+7N=2k+2
19 oveq1 N=2k+2Nmod2=2k+2mod2
20 2t1e2 21=2
21 20 eqcomi 2=21
22 21 a1i k02=21
23 22 oveq2d k02k+2=2k+21
24 2cnd k02
25 1cnd k01
26 adddi 2k12k+1=2k+21
27 26 eqcomd 2k12k+21=2k+1
28 24 9 25 27 syl3anc k02k+21=2k+1
29 9 25 addcld k0k+1
30 24 29 mulcomd k02k+1=k+12
31 23 28 30 3eqtrd k02k+2=k+12
32 31 oveq1d k02k+2mod2=k+12mod2
33 peano2nn0 k0k+10
34 33 nn0zd k0k+1
35 2rp 2+
36 mulmod0 k+12+k+12mod2=0
37 34 35 36 sylancl k0k+12mod2=0
38 32 37 eqtrd k02k+2mod2=0
39 19 38 sylan9eqr k0N=2k+2Nmod2=0
40 8 18 39 syl2an2r Pk0P=k8+7Nmod2=0
41 40 rexlimdva2 Pk0P=k8+7Nmod2=0
42 7 41 syld PPmod8=7Nmod2=0
43 42 imp PPmod8=7Nmod2=0