Description: Equality implies 'less than or equal to'. (Contributed by NM, 4-Apr-2005)
Ref | Expression | ||
---|---|---|---|
Assertion | eqle | ⊢ ( ( 𝐴 ∈ ℝ ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | leid | ⊢ ( 𝐴 ∈ ℝ → 𝐴 ≤ 𝐴 ) | |
2 | breq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝐴 ≤ 𝐴 ↔ 𝐴 ≤ 𝐵 ) ) | |
3 | 2 | biimpac | ⊢ ( ( 𝐴 ≤ 𝐴 ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |
4 | 1 3 | sylan | ⊢ ( ( 𝐴 ∈ ℝ ∧ 𝐴 = 𝐵 ) → 𝐴 ≤ 𝐵 ) |