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Topic:
ALL PERMUTATIONS OF INFINITY
Replies:
4
Last Post:
May 24, 2012 4:55 AM




Re: ALL PERMUTATIONS OF INFINITY
Posted:
May 23, 2012 5:58 AM


Graham Cooper <grahamcooper7@gmail.com> writes:
> On May 22, 7:53 pm, torb...@diku.dk (Torben gidius Mogensen) wrote: >> Graham Cooper <grahamcoop...@gmail.com> writes:
>> > You must have ASSUMED the amount of subsets of N is 2X2X2... = R >> >> Not at all. This is, in fact, fairly easy to prove: We use the theorem >> that there exists a bijection between two sets A and B if there exists >> an injection from A to B and an injection from B to A. So all we need >> to do to prove that P(N) = R is to find injections both ways. >> >> [...] >> >> Since we have injections both ways, the sets are equipotent (i.e., >> having the same size). > > Yes Yes I know all that, you threw a red herring that there is a > bijection between permutations and powersets,
Whay is that a red herring?
> That's like saying there's a bijection between {a,b,c} and {a,b,c,d,e}
There isn't. Do you even know what a bijection is?
Torben



