Description: Reverse closure for a function continuous at a point. (Contributed by Mario Carneiro, 21-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cnprcl2 | ⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑃 ∈ 𝑋 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid | ⊢ ∪ 𝐽 = ∪ 𝐽 | |
| 2 | 1 | cnprcl | ⊢ ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) → 𝑃 ∈ ∪ 𝐽 ) |
| 3 | 2 | adantl | ⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑃 ∈ ∪ 𝐽 ) |
| 4 | toponuni | ⊢ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) → 𝑋 = ∪ 𝐽 ) | |
| 5 | 4 | adantr | ⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑋 = ∪ 𝐽 ) |
| 6 | 3 5 | eleqtrrd | ⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑃 ∈ 𝑋 ) |