Description: A perfectly normal space is normal. (Contributed by Mario Carneiro, 26-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pnrmnrm | ⊢ ( 𝐽 ∈ PNrm → 𝐽 ∈ Nrm ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ispnrm | ⊢ ( 𝐽 ∈ PNrm ↔ ( 𝐽 ∈ Nrm ∧ ( Clsd ‘ 𝐽 ) ⊆ ran ( 𝑥 ∈ ( 𝐽 ↑m ℕ ) ↦ ∩ ran 𝑥 ) ) ) | |
| 2 | 1 | simplbi | ⊢ ( 𝐽 ∈ PNrm → 𝐽 ∈ Nrm ) |