Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: "Chris M. Thomasson" Newsgroups: sci.math Subject: Re: Incompleteness of Cantor's enumeration of the rational numbers (extra-ordinary) Date: Tue, 3 Dec 2024 13:05:25 -0800 Organization: A noiseless patient Spider Lines: 82 Message-ID: References: <71758f338eb239b7419418f49dfd8177c59d778b@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 03 Dec 2024 22:05:26 +0100 (CET) Injection-Info: dont-email.me; posting-host="f777e730b2e8168ebcdb2932c05660c1"; logging-data="363450"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+/tCus+Ag+uroHrY8wlHd9jbz6sad4eDg=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:4Jjqp5KjBRlPBQQarAW8PkI8hwY= In-Reply-To: Content-Language: en-US Bytes: 4790 On 12/3/2024 12:29 AM, Moebius wrote: > Am 03.12.2024 um 07:24 schrieb Moebius: >> Am 03.12.2024 um 07:17 schrieb Chris M. Thomasson: >> >>>>> >>>>>              0 >>>>>             / \ >>>>>            /   \ >>>>>           /     \ >>>>>          /       \ >>>>>         1         2 >>>>>        / \       / \ >>>>>       /   \     /   \ >>>>>      3     4   5     6 >>>>>   ......................... >> >> Though we may take 1 for the root too. This way we would get (using >> binary representation): >> >>  >>>              1 >>  >>>             / \ >>  >>>            /   \ >>  >>>           /     \ >>  >>>          /       \ >>  >>>        10        11 >>  >>>        / \       / \ >>  >>>       /   \     /   \ >>  >>>     100   101 110   111 >>  >>>   ......................... >> >> I guess you get the pattern. :-P > > Another one (without numbers) but /left/ (l), /right/ (r): > >>  >>>              * >>  >>>             / \ >>  >>>            /   \ >>  >>>           /     \ >>  >>>          /       \ >>  >>>         l         r >>  >>>        / \       / \ >>  >>>       /   \     /   \ >>  >>>     ll    lr   rl    rr >>  >>>   ......................... > > This way we may even "identify" each node in the tree with a (finite) l- > r-sequence: > >>  >>>             ()       [<<< the "empty l-r-sequence"] >>  >>>            /  \ >>  >>>           /    \ >>  >>>          /      \ >>  >>>         /        \ >>  >>>       (l)        (r) >>  >>>       / \        / \ >>  >>>      /   \      /   \ >>  >>>   (l,l) (l,r) (r,l) (r,r) >>  >>>   ......................... > > :-P > > So each node actually "is" (or represents) the path leading to it. :-P (l, l) means take two left branches from the root. (r, l) means take one right and one left from the root. I see the pattern. It makes me think some more about my original tree with node, say, 6. It's parent is (6-2)/2 = 2 that is a right (-2) wrt 6 has a parent at 2. At node 2 take a right to get at node 6 Now, lets try 5. It's parent is (5-1)/2 = 2. That is a left from 2 wrt (-1). There is a pattern here as well. At node 2 take a left to get at node 5. Make any sense to you? Thanks.