Saturday, August 13, 2016

real analysis - Construct an explicit bijection f:[0,1]to(0,1], where [0,1] is the closed interval in mathbbR and (0,1] is half open.

The problem:



Construct an explicit bijection f:[0,1](0,1], where [0,1] is the closed interval in R and (0,1] is half open.



My Thoughts:




I imagine that I am to use the fact that there is an injection N[0,1] whose image contains {0} and consider the fact that a set X is infinite iff it contains a proper subset SX with |S|=|X| (because we did something similar in class). I also have a part of proof that we did in class that I believe is supposed to help with this problem; it states the following: Start with an injection g:NX and then define a set S=F(X) where F is an injective (but NOT surjective) function XX with F(x)=x if ximage(g) and f(g(k))=g(2k) if x=g(k)image(g). Honestly, I'm having a lot of trouble even following this proof, so I could be wrong. Anyway, any help here would be appreciated. I feel really lost on this one. Thanks!

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