All the books I read just say that the set of number states (n) forms a complete space. They just say that the sum of all the ket-bra of states n (over all possible n) is equal to unity.(adsbygoogle = window.adsbygoogle || []).push({});

I am having trouble proving this. Can anyone direct me to a good proof and/or show me the way?

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# Completeness of the Number States

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