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Description: The extended real addition operation is commutative. (Contributed by Glauco Siliprandi, 17-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | xaddcomd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ* ) | |
| xaddcomd.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℝ* ) | ||
| Assertion | xaddcomd | ⊢ ( 𝜑 → ( 𝐴 +𝑒 𝐵 ) = ( 𝐵 +𝑒 𝐴 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | xaddcomd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ* ) | |
| 2 | xaddcomd.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℝ* ) | |
| 3 | xaddcom | ⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ) → ( 𝐴 +𝑒 𝐵 ) = ( 𝐵 +𝑒 𝐴 ) ) | |
| 4 | 1 2 3 | syl2anc | ⊢ ( 𝜑 → ( 𝐴 +𝑒 𝐵 ) = ( 𝐵 +𝑒 𝐴 ) ) |