Description: Membership in the set of positive reals. (Contributed by NM, 27-Oct-2007)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elrp | ⊢ ( 𝐴 ∈ ℝ+ ↔ ( 𝐴 ∈ ℝ ∧ 0 < 𝐴 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | breq2 | ⊢ ( 𝑥 = 𝐴 → ( 0 < 𝑥 ↔ 0 < 𝐴 ) ) | |
| 2 | df-rp | ⊢ ℝ+ = { 𝑥 ∈ ℝ ∣ 0 < 𝑥 } | |
| 3 | 1 2 | elrab2 | ⊢ ( 𝐴 ∈ ℝ+ ↔ ( 𝐴 ∈ ℝ ∧ 0 < 𝐴 ) ) |