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Continuity of functions between metric spaces #1375

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@lowasser lowasser marked this pull request as ready for review March 23, 2025 21:04
[metric spaces](metric-spaces.metric-spaces.md) `X` and `Y` is
{{#concept "continuous" WDID=Q170058 WD="continuous function"}} at a point `x`
if there exists a function `m : ℚ⁺ → ℚ⁺` such that whenever `x'` is in an
`m ε`-neighborhood of `x`, `f x'` is in an `ε`-neighborhood of `f x`. `m` is
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Starting a sentence with a mathematical symbol or a code snippet leads to awkward writing, so it is advised to try and avoid it by slight reformulation, e.g., by adding a definite article.

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`m ε`-neighborhood of `x`, `f x'` is in an `ε`-neighborhood of `f x`. `m` is
`m ε`-neighborhood of `x`, `f x'` is in an `ε`-neighborhood of `f x`. The function `m` is

`m ε`-neighborhood of `x`, `f x'` is in an `ε`-neighborhood of `f x`. `m` is
called the modulus of continuity of `f` at `x`.

`f` is called
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`f` is called
The function `f` is called


`f` is called
{{#concept "uniformly continuous" WD="uniformly continuous function" WDID=Q91256217}}
if there is a single `m : ℚ⁺ → ℚ⁺` such that `f` is pointwise continuous with
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if there is a single `m : ℚ⁺ → ℚ⁺` such that `f` is pointwise continuous with
if there is a single function `m : ℚ⁺ → ℚ⁺` such that `f` is pointwise continuous with

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I suggest you add the concept of uniformly continuous functions in a second file. Also, I believe it would be slightly more conventional to call this file continuous-functions-metric-spaces. See for instance the analogous concept scott-continuous-maps-posets in domain theory.

@@ -0,0 +1,99 @@
# Continuity of functions between metric spaces
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# Continuity of functions between metric spaces
# Continuous functions between metric spaces

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