Why any uncountable $G_\delta$ set of $\mathbb{R}$, has a subset homeomorphic to $[0,1]$

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as a continuation to my question here: Is cantor set homeomorphic to the unit interval? I can't see how can it is be true that any uncountable $G_\delta$ set of $\mathbb{R}$, has a subset homeomorphic to $[0,1]$. Isn't the process described here, from John C. Oxtoby's book Measure and Category, similar to the construction of the Cantor set?Lemma 5.1

Thank you!

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To give this an answer, expanding on Carl Mummert's comment:

It doesn't.

Lemma 5.1 of your text asserts that each uncountable $G_\delta$ contains a nowhere dense closed subset $C$ that can be mapped continuously onto $[0,1]$, i.e. there is a continuous surjective map $f : C \to [0,1]$. It is not asserted that $f$ is injective nor that it has a continuous inverse, nor that $C$ is homeomorphic to $[0,1]$ via some other map. In general it is not. For example, if $E$ is the Cantor set, by considering connectedness one can see that any continuous $g : [0,1] \to E$ is constant, so no surjective $f : C \to [0,1]$ can possibly have a continuous inverse.