Description: Define the set of open intervals of extended reals. (Contributed by NM, 24-Dec-2006)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-ioo | ⊢ (,) = ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥 < 𝑧 ∧ 𝑧 < 𝑦 ) } ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cioo | ⊢ (,) | |
| 1 | vx | ⊢ 𝑥 | |
| 2 | cxr | ⊢ ℝ* | |
| 3 | vy | ⊢ 𝑦 | |
| 4 | vz | ⊢ 𝑧 | |
| 5 | 1 | cv | ⊢ 𝑥 |
| 6 | clt | ⊢ < | |
| 7 | 4 | cv | ⊢ 𝑧 |
| 8 | 5 7 6 | wbr | ⊢ 𝑥 < 𝑧 |
| 9 | 3 | cv | ⊢ 𝑦 |
| 10 | 7 9 6 | wbr | ⊢ 𝑧 < 𝑦 |
| 11 | 8 10 | wa | ⊢ ( 𝑥 < 𝑧 ∧ 𝑧 < 𝑦 ) |
| 12 | 11 4 2 | crab | ⊢ { 𝑧 ∈ ℝ* ∣ ( 𝑥 < 𝑧 ∧ 𝑧 < 𝑦 ) } |
| 13 | 1 3 2 2 12 | cmpo | ⊢ ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥 < 𝑧 ∧ 𝑧 < 𝑦 ) } ) |
| 14 | 0 13 | wceq | ⊢ (,) = ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥 < 𝑧 ∧ 𝑧 < 𝑦 ) } ) |