Description: Identity law for multiplication. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | addcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| Assertion | mulridd | ⊢ ( 𝜑 → ( 𝐴 · 1 ) = 𝐴 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | addcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| 2 | mulrid | ⊢ ( 𝐴 ∈ ℂ → ( 𝐴 · 1 ) = 𝐴 ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ( 𝐴 · 1 ) = 𝐴 ) |