Description: Equality implies 'less than or equal to'. (Contributed by Glauco Siliprandi, 17-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xreqle | ⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | xrleid | ⊢ ( 𝐴 ∈ ℝ* → 𝐴 ≤ 𝐴 ) | |
| 2 | 1 | adantr | ⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐴 ) |
| 3 | simpr | ⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐴 = 𝐵 ) → 𝐴 = 𝐵 ) | |
| 4 | breq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝐴 ≤ 𝐴 ↔ 𝐴 ≤ 𝐵 ) ) | |
| 5 | 4 | biimpac | ⊢ ( ( 𝐴 ≤ 𝐴 ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |
| 6 | 2 3 5 | syl2anc | ⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |