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Description: Distributive law for the multiplication operation of a ring (left-distributivity). (Contributed by Steve Rodriguez, 9-Sep-2007)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ringdi.b | ⊢ 𝐵 = ( Base ‘ 𝑅 ) | |
| ringdi.p | ⊢ + = ( +g ‘ 𝑅 ) | ||
| ringdi.t | ⊢ · = ( .r ‘ 𝑅 ) | ||
| Assertion | ringdi | ⊢ ( ( 𝑅 ∈ Ring ∧ ( 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵 ) ) → ( 𝑋 · ( 𝑌 + 𝑍 ) ) = ( ( 𝑋 · 𝑌 ) + ( 𝑋 · 𝑍 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ringdi.b | ⊢ 𝐵 = ( Base ‘ 𝑅 ) | |
| 2 | ringdi.p | ⊢ + = ( +g ‘ 𝑅 ) | |
| 3 | ringdi.t | ⊢ · = ( .r ‘ 𝑅 ) | |
| 4 | 1 2 3 | ringdilem | ⊢ ( ( 𝑅 ∈ Ring ∧ ( 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵 ) ) → ( ( 𝑋 · ( 𝑌 + 𝑍 ) ) = ( ( 𝑋 · 𝑌 ) + ( 𝑋 · 𝑍 ) ) ∧ ( ( 𝑋 + 𝑌 ) · 𝑍 ) = ( ( 𝑋 · 𝑍 ) + ( 𝑌 · 𝑍 ) ) ) ) |
| 5 | 4 | simpld | ⊢ ( ( 𝑅 ∈ Ring ∧ ( 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵 ) ) → ( 𝑋 · ( 𝑌 + 𝑍 ) ) = ( ( 𝑋 · 𝑌 ) + ( 𝑋 · 𝑍 ) ) ) |