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I completed my studies at McGill University/Montral in the 1980s. I still have all my course notes, which are in impeccable condition (several thousand handwritten...
This is an example from Munkres Topology book. In this example, it is shown that has no countable basis. However it makes use...
I have always thought that Urysohn's Metrization Theorem is not provable in ZF and you need to use at least the axiom of dependant choice(DC)...
i know the induction proof and the picture of stacking l-shaped layers into a square, but i'm trying to explain it to a student who...