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diff --git a/pages/general-topology/continuity-and-convergence.md b/pages/general-topology/continuity-and-convergence.md new file mode 100644 index 0000000..7ae4534 --- /dev/null +++ b/pages/general-topology/continuity-and-convergence.md @@ -0,0 +1,24 @@ +--- +title: Continuity & Convergence +parent: General Topology +nav_order: 2 +--- + +# {{ page.title }} + +{% definition Continuity %} +A mapping $f: X \to Y$ between topological spaces $X$ and $Y$ is called *continuous*, +if for each open subset $V$ of $Y$ the inverse image $f^{-1}(V)$ is an open subset of $X$. +{% enddefinition %} + +Slogan: continuous $=$ The inverse image of every open subset is open. + +{% definition Homeomorphism %} +Suppose $X$ and $Y$ are topological spaces. +A mapping $f: X \to Y$ is said to be a *homeomorphism*, +if $f$ is bijective and both $f$ and the inverse mapping $f^{-1} : Y \to X$ are continuous. +{% enddefinition %} + +## Nets + +## Filters |