Metamath Proof Explorer


Theorem 2lgsoddprmlem1

Description: Lemma 1 for 2lgsoddprm . (Contributed by AV, 19-Jul-2021)

Ref Expression
Assertion 2lgsoddprmlem1 A B N = 8 A + B N 2 1 8 = 8 A 2 + 2 A B + B 2 1 8

Proof

Step Hyp Ref Expression
1 oveq1 N = 8 A + B N 2 = 8 A + B 2
2 1 3ad2ant3 A B N = 8 A + B N 2 = 8 A + B 2
3 2 oveq1d A B N = 8 A + B N 2 1 = 8 A + B 2 1
4 3 oveq1d A B N = 8 A + B N 2 1 8 = 8 A + B 2 1 8
5 zcn A A
6 5 adantr A B A
7 zcn B B
8 7 adantl A B B
9 1cnd A B 1
10 8cn 8
11 8re 8
12 8pos 0 < 8
13 11 12 gt0ne0ii 8 0
14 10 13 pm3.2i 8 8 0
15 14 a1i A B 8 8 0
16 mulsubdivbinom2 A B 1 8 8 0 8 A + B 2 1 8 = 8 A 2 + 2 A B + B 2 1 8
17 6 8 9 15 16 syl31anc A B 8 A + B 2 1 8 = 8 A 2 + 2 A B + B 2 1 8
18 17 3adant3 A B N = 8 A + B 8 A + B 2 1 8 = 8 A 2 + 2 A B + B 2 1 8
19 4 18 eqtrd A B N = 8 A + B N 2 1 8 = 8 A 2 + 2 A B + B 2 1 8