Database
BASIC TOPOLOGY
Topology
Local topological properties
nllytop
Next ⟩
llyi
Metamath Proof Explorer
Ascii
Unicode
Theorem
nllytop
Description:
A locally
A
space is a topological space.
(Contributed by
Mario Carneiro
, 2-Mar-2015)
Ref
Expression
Assertion
nllytop
⊢
J
∈
N-Locally
A
→
J
∈
Top
Proof
Step
Hyp
Ref
Expression
1
isnlly
⊢
J
∈
N-Locally
A
↔
J
∈
Top
∧
∀
x
∈
J
∀
y
∈
x
∃
u
∈
nei
⁡
J
⁡
y
∩
𝒫
x
J
↾
𝑡
u
∈
A
2
1
simplbi
⊢
J
∈
N-Locally
A
→
J
∈
Top