- #76

fresh_42

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##\pi^{-1}(\pi(U)) =U \neq_{i.g} gK##One surprising fact to me is the fact that ##\pi## is open implies that if there is an open set ##U \in gK##, then the entire coset is open, since ##\pi^{-1}(\pi(U)) = gK##. This must be related to 5.5.

##\pi## is open means that it maps open sets to open sets, so there are open neighborhoods around the images of those points.