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Description: Addition of positive and nonnegative numbers is positive. (Contributed by Asger C. Ipsen, 12-May-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | leidd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| ltnegd.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℝ ) | ||
| addgtge0d.3 | ⊢ ( 𝜑 → 0 < 𝐴 ) | ||
| addgtge0d.4 | ⊢ ( 𝜑 → 0 ≤ 𝐵 ) | ||
| Assertion | addgtge0d | ⊢ ( 𝜑 → 0 < ( 𝐴 + 𝐵 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | leidd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| 2 | ltnegd.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℝ ) | |
| 3 | addgtge0d.3 | ⊢ ( 𝜑 → 0 < 𝐴 ) | |
| 4 | addgtge0d.4 | ⊢ ( 𝜑 → 0 ≤ 𝐵 ) | |
| 5 | addgtge0 | ⊢ ( ( ( 𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ) ∧ ( 0 < 𝐴 ∧ 0 ≤ 𝐵 ) ) → 0 < ( 𝐴 + 𝐵 ) ) | |
| 6 | 1 2 3 4 5 | syl22anc | ⊢ ( 𝜑 → 0 < ( 𝐴 + 𝐵 ) ) |