Definition:Path Component
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Definition
Let $T$ be a topological space.
Equivalence Class
Let $\sim$ be the equivalence relation on $T$ defined as:
- $x \sim y \iff x$ and $y$ are path-connected.
The equivalence classes of $\sim$ are called the path components of $T$.
If $x \in T$, then the path component of $T$ containing $x$ (that is, the set of points $y \in T$ with $x \sim y$) can be denoted by $\map {\operatorname{PC}_x} T$.
Union of Path-Connected Sets
The path component of $T$ containing $x$ is defined as:
- $\ds \map {\operatorname{PC}_x} T = \bigcup \leftset {A \subseteq S: x \in A \land A}$ is path-connected $\rightset {}$
Maximal Path-Connected Set
The path component of $T$ containing $x$ is defined as:
- the maximal path-connected set of $T$ that contains $x$.