Metamath Proof Explorer


Theorem distrpi

Description: Multiplication of positive integers is distributive. (Contributed by NM, 21-Sep-1995) (New usage is discouraged.)

Ref Expression
Assertion distrpi A 𝑵 B + 𝑵 C = A 𝑵 B + 𝑵 A 𝑵 C

Proof

Step Hyp Ref Expression
1 pinn A 𝑵 A ω
2 pinn B 𝑵 B ω
3 pinn C 𝑵 C ω
4 nndi A ω B ω C ω A 𝑜 B + 𝑜 C = A 𝑜 B + 𝑜 A 𝑜 C
5 1 2 3 4 syl3an A 𝑵 B 𝑵 C 𝑵 A 𝑜 B + 𝑜 C = A 𝑜 B + 𝑜 A 𝑜 C
6 addclpi B 𝑵 C 𝑵 B + 𝑵 C 𝑵
7 mulpiord A 𝑵 B + 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑜 B + 𝑵 C
8 6 7 sylan2 A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑜 B + 𝑵 C
9 addpiord B 𝑵 C 𝑵 B + 𝑵 C = B + 𝑜 C
10 9 oveq2d B 𝑵 C 𝑵 A 𝑜 B + 𝑵 C = A 𝑜 B + 𝑜 C
11 10 adantl A 𝑵 B 𝑵 C 𝑵 A 𝑜 B + 𝑵 C = A 𝑜 B + 𝑜 C
12 8 11 eqtrd A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑜 B + 𝑜 C
13 12 3impb A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑜 B + 𝑜 C
14 mulclpi A 𝑵 B 𝑵 A 𝑵 B 𝑵
15 mulclpi A 𝑵 C 𝑵 A 𝑵 C 𝑵
16 addpiord A 𝑵 B 𝑵 A 𝑵 C 𝑵 A 𝑵 B + 𝑵 A 𝑵 C = A 𝑵 B + 𝑜 A 𝑵 C
17 14 15 16 syl2an A 𝑵 B 𝑵 A 𝑵 C 𝑵 A 𝑵 B + 𝑵 A 𝑵 C = A 𝑵 B + 𝑜 A 𝑵 C
18 mulpiord A 𝑵 B 𝑵 A 𝑵 B = A 𝑜 B
19 mulpiord A 𝑵 C 𝑵 A 𝑵 C = A 𝑜 C
20 18 19 oveqan12d A 𝑵 B 𝑵 A 𝑵 C 𝑵 A 𝑵 B + 𝑜 A 𝑵 C = A 𝑜 B + 𝑜 A 𝑜 C
21 17 20 eqtrd A 𝑵 B 𝑵 A 𝑵 C 𝑵 A 𝑵 B + 𝑵 A 𝑵 C = A 𝑜 B + 𝑜 A 𝑜 C
22 21 3impdi A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 A 𝑵 C = A 𝑜 B + 𝑜 A 𝑜 C
23 5 13 22 3eqtr4d A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑵 B + 𝑵 A 𝑵 C
24 dmaddpi dom + 𝑵 = 𝑵 × 𝑵
25 0npi ¬ 𝑵
26 dmmulpi dom 𝑵 = 𝑵 × 𝑵
27 24 25 26 ndmovdistr ¬ A 𝑵 B 𝑵 C 𝑵 A 𝑵 B + 𝑵 C = A 𝑵 B + 𝑵 A 𝑵 C
28 23 27 pm2.61i A 𝑵 B + 𝑵 C = A 𝑵 B + 𝑵 A 𝑵 C