Description: Identity law for natural multiplication. Deduction form. (Contributed by Scott Fenton, 30-Jul-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nmul.1 | ⊢ ( 𝜑 → 𝐴 ∈ On ) | |
| Assertion | nmulridd | ⊢ ( 𝜑 → ( 𝐴 ·no 1o ) = 𝐴 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nmul.1 | ⊢ ( 𝜑 → 𝐴 ∈ On ) | |
| 2 | nmulrid | ⊢ ( 𝐴 ∈ On → ( 𝐴 ·no 1o ) = 𝐴 ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ( 𝐴 ·no 1o ) = 𝐴 ) |