Metamath Proof Explorer
Description: Commutative law for multiplication. (Contributed by NM, 23-Nov-1994)
|
|
Ref |
Expression |
|
Hypotheses |
axi.1 |
⊢ 𝐴 ∈ ℂ |
|
|
axi.2 |
⊢ 𝐵 ∈ ℂ |
|
|
mulcomli.3 |
⊢ ( 𝐴 · 𝐵 ) = 𝐶 |
|
Assertion |
mulcomli |
⊢ ( 𝐵 · 𝐴 ) = 𝐶 |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
axi.1 |
⊢ 𝐴 ∈ ℂ |
2 |
|
axi.2 |
⊢ 𝐵 ∈ ℂ |
3 |
|
mulcomli.3 |
⊢ ( 𝐴 · 𝐵 ) = 𝐶 |
4 |
2 1
|
mulcomi |
⊢ ( 𝐵 · 𝐴 ) = ( 𝐴 · 𝐵 ) |
5 |
4 3
|
eqtri |
⊢ ( 𝐵 · 𝐴 ) = 𝐶 |