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Mathematics
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Topology
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Neighborhood definition
Neighborhood definition
A fundamental concept in topology characterizing the 'nearness' of points.
📜
The statement of the theorem
A set
V
V
V
is a neighborhood of
x
x
x
if there is an open set
U
U
U
such that
x
∈
U
⊆
V
x \in U \subseteq V
x
∈
U
⊆
V
.