Nayuki Minase
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 Apr23 awarded Excavator Apr23 revised Confusing about logic gates Domain name change Apr23 revised Good introductory books on primitive recursive functions Domain name change Apr23 awarded Teacher Apr23 suggested approved edit on Good introductory books on primitive recursive functions Apr23 answered Applying Fibonacci Fast Doubling Identities Apr23 suggested approved edit on Confusing about logic gates Nov7 awarded Popular Question Sep28 awarded Critic Sep28 comment How to write this in mathematical notation? In your question, "either x or y" is misleading because it is possible for both x and y to be irrational and have their product be irrational too. Sep24 awarded Popular Question Apr16 comment Prove that $\lfloor \lfloor x / a\rfloor / b \rfloor = \lfloor x / (ab) \rfloor$ (a) Is $k$ constrained to be an integer? (b) How does your proof address the fact that $m$ and $n$ must be positive integers (not arbitrary real numbers)? Apr16 comment Prove that $\lfloor \lfloor x / a\rfloor / b \rfloor = \lfloor x / (ab) \rfloor$ @MathGems: I looked at your proof, but I'm not convinced about why those bi-implications are true. I found the proof by Brian M. Scott to be better explained and easier for me to understand. Apr13 comment Prove that $\lfloor \lfloor x / a\rfloor / b \rfloor = \lfloor x / (ab) \rfloor$ Wow André, that was a pretty terse hint. But with some work, I was able to expand it into a full solution. Thanks! Apr13 comment Prove that $\lfloor \lfloor x / a\rfloor / b \rfloor = \lfloor x / (ab) \rfloor$ You're right. Though I feel embarrassed about asking a duplicate question, I'd like thank you very much! Apr13 asked Prove that $\lfloor \lfloor x / a\rfloor / b \rfloor = \lfloor x / (ab) \rfloor$ Mar3 awarded Commentator Mar3 comment Prove that if $2^n-1$ is prime, then $n$ divides $2^n-2$ I mean introduction of a new variable, whose role and meaning is unexplained. Mar3 comment Prove that if $2^n-1$ is prime, then $n$ divides $2^n-2$ I am extremely uncomfortable with how much you left implied, such as the instantiation of $K$, the references to GCD, and the very non-obvious invocation of Fermat's little theorem for $K$. Only after rereading your proof a few times on separate days did I start to believe that it plausibly leads to an answer at all. -1. Mar3 comment Prove that if $2^n-1$ is prime, then $n$ divides $2^n-2$ I didn't understand how your answer fits with my question. Please see the other answers as examples of proofs that I did understand.