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Path: ...!feeds.phibee-telecom.net!weretis.net!feeder6.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: Richard Damon <richard@damon-family.org> Newsgroups: comp.theory Subject: Re: Repeating decimals are irrational Date: Wed, 27 Mar 2024 23:02:49 -0400 Organization: i2pn2 (i2pn.org) Message-ID: <uu2mkp$374vo$19@i2pn2.org> References: <e9009d933dc0c3008201ba6cfced892d235192c8.camel@gmail.com> <utvvkk$35q21$2@i2pn2.org> <9e63d5d9c0cadc8e6372a1d7dbff5e257c65b4ff.camel@gmail.com> <uu2fou$374vo$10@i2pn2.org> <973069b02f7ef549ca9c90c4afb1698c2c19096d.camel@gmail.com> <uu2jhm$374vn$3@i2pn2.org> <d303de0d204c180ee877d8de25f3ff9390dd3274.camel@gmail.com> <uu2l78$374vo$14@i2pn2.org> <b10756fc935e84905245bf50bce5c7a4957af55d.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 28 Mar 2024 03:02:50 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="3380216"; mail-complaints-to="usenet@i2pn2.org"; posting-account="diqKR1lalukngNWEqoq9/uFtbkm5U+w3w6FQ0yesrXg"; User-Agent: Mozilla Thunderbird X-Spam-Checker-Version: SpamAssassin 4.0.0 In-Reply-To: <b10756fc935e84905245bf50bce5c7a4957af55d.camel@gmail.com> Content-Language: en-US Bytes: 7442 Lines: 164 On 3/27/24 10:45 PM, wij wrote: > On Wed, 2024-03-27 at 22:38 -0400, Richard Damon wrote: >> On 3/27/24 10:18 PM, wij wrote: >>> On Wed, 2024-03-27 at 22:09 -0400, Richard Damon wrote: >>>> On 3/27/24 10:01 PM, wij wrote: >>>>> On Wed, 2024-03-27 at 21:05 -0400, Richard Damon wrote: >>>>>> On 3/27/24 8:56 PM, wij wrote: >>>>>>> On Tue, 2024-03-26 at 22:17 -0400, Richard Damon wrote: >>>>>>>> On 3/26/24 10:45 AM, wij wrote: >>>>>>>>> Snipet from >>>>>>>>> https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber-en.txt/download >>>>>>>>> >>>>>>>>> ... >>>>>>>>> Real Nunmber(ℝ)::= {x| x is represented by n-ary <fixed_point_number>, the >>>>>>>>> digits may be infinitely long } >>>>>>>>> >>>>>>>>> Note: This definition implies that repeating decimals are irrational number. >>>>>>>>> Let's list a common magic proof in the way as a brief explanation: >>>>>>>>> (1) x= 0.999... >>>>>>>>> (2) 10x= 9+x // 10x= 9.999... >>>>>>>>> (3) 9x=9 >>>>>>>>> (4) x=1 >>>>>>>>> Ans: There is no axiom or theorem to prove (1) => (2). >>>>>>>>> >>>>>>>>> Note: If the steps of converting a number x to <fixed_point_number> is not >>>>>>>>> finite, x is not a ratio of two integers, because the following >>>>>>>>> statement is always true: ∀x,a∈ℚ, x-a∈ℚ >>>>>>>>> >>>>>>>>> ---End of quote >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> So, if 10 * 0.999... isn't 9.999... what is it? >>>>>>>> and if 9 + 0.999... isnt 9.999... what is it? >>>>>>>> >>>>>>>> And why aren't the same numbers the same numbers. >>>>>>>> >>>>>>>> So, either your "wij-Reals" just fail to have the normal mathematical >>>>>>>> operations defined or you have a problem with the proof. >>>>>>>> >>>>>>>> Numbers defined with no rules on how to manipulate them are fairly >>>>>>>> worthless. >>>>>>> >>>>>>> The update was available: >>>>>>> https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber-en.txt/download >>>>>>> >>>>>>> Hope, it can solve your doubt. >>>>>>> >>>>>> >>>>>> But the name "Real" is still very bad. >>>>>> >>>>>> Particularly since you seem to say that any number that can't be >>>>>> expressed in a finite number of digits in SOME base, is not a number in >>>>>> your system, >>>>> >>>>> I did not say that. ℝ just numbers expressible by <fixed_point_number>. >>>> Near the top of the paper is: >>>> >>>> >>>> +-------------+ >>>>> Real Number | >>>> +-------------+ >>>> >>>> >>>> >>>> >>>>> >>>>>> since they can not be explicitly defined, OR HAVE MATH DONE >>>>>> ON THEM, since >>>>>> >>>>>> 0.9999.... * 10 = 9. and somethnig not defined after it. (it isn't even >>>>>> .999...) >>>>>> >>>>> >>>>> What are you referring to? >>>>> >>>> >>>> >>>> >>>> IOW, by repeatedly multiplying 0.999... with 10, you can only see 9, >>>> the structure of the rear end of 0.999... is never seen. >>>> >>>> >>> Will you explain more specific? I did not mention anything "0.9999.... * 10 = 9. and somethnig not >>> defined after it. (it isn't even >>> .999...)" >> >> The line above was taken directly from the paper that I downloaded by >> clicking on the link. >> >> You say, and I quote: >> >> 0.999.... * 10 = 9. and somthing not defined after it. (it isn't even >> .999...) >> >> > I uploaded again: What/where were you referring to? > -------------------------- > > +-------------+ > | Real Number | > +-------------+ > > n-ary Fixed-Point Number::= Number represented by a string of digits, the > string may contain a minus sign or a point: > > <fixed_point_number>::= [-] <dstr1> [ . <dstr2> ] > <dstr1>::= 0 | <nzd> { 0, <nzd> } > <dstr2>::= { 0, <nzd> } <nzd> > <nzd> ::= (1, 2, 3, 4, 5, 6, 7, 8, 9) // 'digit' varys depending on n-ary > > Two n-ary fixed-point number (same n-ary) x,y are equal iff their > <fixed_point_number> representation are identical. > > Real Nunmber(ℝ)::= {x| x is finitely represented by n-ary <fixed_point_number> > and those that cannot be finitely represented } > > Note: Numbers that is not finitely representable cannot all be explicitly > defined, this is the property of real number based on discrete symbols > (like quantum?). E.g. > > A= lim(n->∞) 1-3/10^n = 0.999... > B= lim(n->∞) 1-2/2^n = 0.999... > C= lim(n->∞) 1-1/n = 0.999... > ... > > IOW, by repeatedly multiplying 0.999... with 10, you can only see 9, > the structure of the rear end of 0.999... is not seen. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Note: This definition implies that repeating decimals are irrational number. > Let's list a common magic proof in the way as a brief explanation: > (1) x= 0.999... > (2) 10x= 9+x // 10x= 9.999... > (3) 9x=9 > (4) x=1 > Ans: There is no axiom or theorem to prove (1) => (2). > > Note: To determine whether a repeating decimal x is rational or not, we can > repeatedly subtract the repeating pattern p(i) from x. > If x-p(1)-p(2)-...=0 can be verified in finite steps, then x is > rational. Otherwise, x is irrational, because, if x is rational, the > last remaining piece r(i)= x-p(1)-p(2)-... must exactly be the > repeating pattern p(i). But, by definition of 'repeating', r(i) cannot > be pattern p(i). Therefore, repeating decimal is irrational. > > >> >>> >>>> >>>>>> So, your system seems more to be just the rationals. and you don't seem >>>>>> to provide a clear set of axioms of what you allow to be done with these >>>>>> numbers. >>>>> >>>>> >>>>> >>>> >>> >>> >> > >