Description: A commutative monoid is a monoid. (Contributed by Mario Carneiro, 6-Jan-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cmnmnd | ⊢ ( 𝐺 ∈ CMnd → 𝐺 ∈ Mnd ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid | ⊢ ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 ) | |
| 2 | eqid | ⊢ ( +g ‘ 𝐺 ) = ( +g ‘ 𝐺 ) | |
| 3 | 1 2 | iscmn | ⊢ ( 𝐺 ∈ CMnd ↔ ( 𝐺 ∈ Mnd ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐺 ) ∀ 𝑦 ∈ ( Base ‘ 𝐺 ) ( 𝑥 ( +g ‘ 𝐺 ) 𝑦 ) = ( 𝑦 ( +g ‘ 𝐺 ) 𝑥 ) ) ) |
| 4 | 3 | simplbi | ⊢ ( 𝐺 ∈ CMnd → 𝐺 ∈ Mnd ) |