Logic — math, philosophy & computational aspects

logic, math, philosophy, math games, math help, mathematical logic, philosophy of education, math facts




Re: wanted: proofs that 0 = 1

In article <1ran8nINN…@darkstar.UCSC.EDU> i…@cse.ucsc.edu (ian barland (worm canner)) writes:

>Hi, i’m looking for simple, short, (but convincing :-) proofs that 0 = 1.

Let X be the statement: if X then 0 = 1.

In particular, X is the statement:
          "’implies 0 = 1 if preceded by its quotation’
            implies 0 = 1 if preceded by its quotation"

(1) Proof that X implies 0 = 1:
Assume X.  Then by definition, if X then 0 = 1.  Therefore 0 = 1.

(2) Proof of X:
Since we have just shown that X implies 0 = 1, we’ve just proven the statement
if X then 0 = 1, thus by definition, X.

(3) Proof of 0 = 1:
Taking (1) and (2) together, it follows that 0 = 1.

posted by admin in Uncategorized and have Comments (24)






24 Responses to “Re: wanted: proofs that 0 = 1”

  1. admin says:

    In article <1rjl3pINN…@uwm.edu>, ma…@csd4.csd.uwm.edu (Mark) writes:

    |> In article <1ran8nINN…@darkstar.UCSC.EDU> i…@cse.ucsc.edu (ian barland (worm canner)) writes:
    |> >Hi, i’m looking for simple, short, (but convincing :-) proofs that 0 = 1.
    |>
    |> Let X be the statement: if X then 0 = 1.
    |>
    |> In particular, X is the statement:
    |>           "’implies 0 = 1 if preceded by its quotation’
    |>             implies 0 = 1 if preceded by its quotation"
    |>
    |> (1) Proof that X implies 0 = 1:
    |> Assume X.  Then by definition, if X then 0 = 1.  Therefore 0 = 1.
    |>
    |> (2) Proof of X:
    |> Since we have just shown that X implies 0 = 1, we’ve just proven the statement
    |> if X then 0 = 1, thus by definition, X.
    |>
    |> (3) Proof of 0 = 1:
    |> Taking (1) and (2) together, it follows that 0 = 1.

    Or, …

          +————————————–+
          | Every sentence in the box is false.  |
          | 0 = 1                                |
          +————————————–+

    Proof is left as an exercise.

    But I don’t think these are "convincing".  The "best" type of
    proof I’ve seen of this sort involves an algebraic
    derivation in which a division by zero is performed (but
    concealed by subtracting variables).


    Gary H. Merrill  [Principal Systems Developer, C Compiler Development]
    SAS Institute Inc. / SAS Campus Dr. / Cary, NC  27513 / (919) 677-8000
    sas…@theseus.unx.sas.com … !mcnc!sas!sasghm

  2. admin says:

    I was asked to forward this response.  Please respond to the person indicated
    below and not to me.

    From: r…@acpub.duke.edu (Ray Ubinger)
    Date: Tue, 27 Apr 93 21:19:23 -0400
    Subject: Re: wanted: proofs that 0 = 1
    Organization: Duke University; Durham, N.C.

    I’m so new to this medium that I’m not sure whether I’m sending personal
    mail here or posting to the group.  Please do forward this to the group
    at large if it’s personal mail to you alone.

    The posting a day or two ago of a proof that 0=1 was the best I’ve ever
    seen.  It applies the formula for integration by parts,
    int[u dv] = uv – int[v du]
    on the integrand u = 1/x, dv = dx.

    WHERE’S THE FALLACY is the fun question of these kinds of "proofs."
    The temptation in refuting the above is to say that int[dx/x] equals
    natural log of absolute value of x (plus arbitrary constant) and
    "therefore" the 0 = 1 proof must be wrong.  But this only shows that
    one or both statements ar wrong, and does not disprove the argument.

    I am pretty sure, but not rigorously so, that the proof errs on this
    count:  the integration-by-parts formula is simply not valid for the
    function 1/x.  Reason:  that formula is derived from the product rule
    for differentiation:
    d(uv) = u dv + v du  (integrate both sides and isolate int[u dv]

    BUT … but but BUT … That product rule has the hypothesis-assumption
    that u and v must be DIFFERENTIABLE functions!  Since 1/x does not
    qualify, being discontinuous (yea, undefined) at x = 0, the argument
    collapses.

    The rare charm of this spurious 0=1 proof (sigh, aren’t they all
    spurious?) is that it employs the higher level of calculus instead of
    the much more familiar ones which sneak in division by zero with
    junior-high-school algebra.

    AND NOW, a new 0=1 proof.  Find the fallacy.  Hint:  I don’t divide
    by zero in it.

    Statement                          Reason

    x^2 = x + x + … + x              e.g., 2^2 = 2 + 2
                                              5^2 = 5 + 5 + 5 + 5 + 5
          ^^^^^^^^^^^^^^^
            x times

    2x = 1 + 1 + … + 1               Differentiate both sides with respect
         ^^^^^^^^^^^^^^^               to x.
            x times

    2x = x                             Sum of 1-sub-i from 1=1 up to x
                                       equals x.

    2 = 1                              Divide both sides by x.  If x = 0, this
                                       is disallowed, true, but then again x
                                       was arbitrary from the outset, so x
                                       equalling zero means EVERY number equals
                                       zero, in which case 1 in particular
                                       equals zero (Q.E.D. for case x = 0; if
                                        x does not equal zero then the division
                                       in this step is allowable and we continue
                                       now from the statement 2=1).

    1 = 0                              Subtract 1 from each side.  Q.E.D.

    Enjoy, y’all.  Hope this makes it onto the group posting.

    Ray Ubinger, Durham NC
    (919) 682-3683
    r…@acpub.duke.edu    "Duke Basketball Three-peat in ’96!"

  3. admin says:

    In article <C65IKq….@unx.sas.com> sas…@theseus.unx.sas.com (Gary Merrill) writes:

    #
    #But I don’t think these are "convincing".  The "best" type of
    #proof I’ve seen of this sort involves an algebraic
    #derivation in which a division by zero is performed (but
    #concealed by subtracting variables).

    The best "proofs" I have seen are by computing primitives.
    Ordinary operations, which are legally used to compute primitives
    or recursive relations between primitives, give then: P = P + 1.
    This is entirely correct, if one realizes that a primitive actually
    is a class of functions, the members of the class differing by constants.

    In a sense 0 = 1 can be interpreted as saying that both members are
    a primitive of the zero function.

    JWN

  4. admin says:

    Hey you cheaters…
    All this comes from a great book: Fallacies in mathematics.
    It’s a red-pupleish small paperback. I can’t remember who’s the
    author, but it’s an english or american math prof.
    larry

  5. admin says:

    The first I ever saw, in maybe 9th grade, was this:
    Let x = 1 and let y = 1. Then x = y.
    Multiplying both sides by -y gives: -x*y = -y*y.
    Adding x*x to both sides gives: x*x – x*y = x*x – y*y.
    Factoring gives: x*(x-y) = (x+y)*(x-y).
    Dividing through by (x-y) gives:  x = x + y.
    Subtracting x from both sides gives: 0 = y.
    Since y = 1, we have: 0 = 1.

    Daryl McCullough
    ORA Corp.
    Ithaca, NY

  6. admin says:

    >>>>> On Wed, 28 Apr 1993 15:22:59 GMT, da…@oracorp.com (Daryl McCullough) said:

     >> The first I ever saw, in maybe 9th grade, was this:
     >> Let x = 1 and let y = 1. Then x = y.
     >> Multiplying both sides by -y gives: -x*y = -y*y.
     >> Adding x*x to both sides gives: x*x – x*y = x*x – y*y.
     >> Factoring gives: x*(x-y) = (x+y)*(x-y).
     >> Dividing through by (x-y) gives:  x = x + y.
     >> Subtracting x from both sides gives: 0 = y.
     >> Since y = 1, we have: 0 = 1.

     >> Daryl McCullough
     >> ORA Corp.
     >> Ithaca, NY

    A similar "proof" that pi = 3 (once almost legislated in Texas)
    was shown to me as a freshman in college.

    First suggest that (pi + 3) = 2t for some t.  Most freshman will
    pause for a moment and convince themselves that this is probably
    ok.  Then execute the following steps:

    Multiply by (pi – 3):  (pi + 3)(pi – 3) = 2t(pi – 3)
    Expand:                        pi^2 – 9 = 2t*pi – 6t
    Rearrange:                -2t*pi + pi^2 = -6t + 9
    Add t^2:             t^2 – 2t*pi + pi^2 = t^2 – 6t + 9
    Factor:                      (t – pi)^2 = (t – 3)^2
    Square root:                   (t – pi) = (t – 3)
    Eliminate t:                        -pi = -3
    Multiply by -1:                      pi = 3    Voila.

    Pete

    +——————————————————————–+
    |             No matter where you go…there you are.                |
    |                                                                    |
    | Remember, you can ALWAYS lie on a                                  |
    | set of measure zero.  (Andrew Rosalsky)        pet…@stat.ufl.edu |
    +——————————————————————–+

  7. admin says:

    Mark (ma…@csd4.csd.uwm.edu) wrote:

    : In article <1ran8nINN…@darkstar.UCSC.EDU> i…@cse.ucsc.edu (ian barland (worm canner)) writes:
    : >Hi, i’m looking for simple, short, (but convincing :-) proofs that 0 = 1.

    : Let X be the statement: if X then 0 = 1.

    : In particular, X is the statement:
    :           "’implies 0 = 1 if preceded by its quotation’
    :             implies 0 = 1 if preceded by its quotation"

    : (1) Proof that X implies 0 = 1:
    : Assume X.  Then by definition, if X then 0 = 1.  Therefore 0 = 1.

    : (2) Proof of X:
    : Since we have just shown that X implies 0 = 1, we’ve just proven the statement
    : if X then 0 = 1, thus by definition, X.

    : (3) Proof of 0 = 1:
    : Taking (1) and (2) together, it follows that 0 = 1.

    This argument involves the implicit use of fixed points. The fixed point
    in question is false. One also has the contrapositive
                            0 != 1 => NOT X
    Since 0 != 1, one concludes NOT X, so that X and NOT X hold. So X is false.

    X can be regarded as an extreme solution of a Boolean equation
                            Y : Y => 0 = 1

    I hope that you aren’t as bored reading this as I was writing it.

    Florian
    mutat…@dorsai.dorsai.org

  8. admin says:

    The lattice theorists proof of 0 = 1

    1 < 2. Taking meets we have 1.2 = 1 ie 2 = 1. Subtracting 1 from both side
    gives the result :)

    Colin

  9. admin says:

    The most elegant proofs in Mathematics usually use complex numbers. Here  
    are three of them:

    1. THEOREM. -1 = 1.

    Proof: -1 = i^2 = i \dot i = \sqrt{-1}\dot\sqrt{-1} =
           \sqrt{(-1)(-1)} = \sqrt{1} = 1.

    COROLLARY (The Main Theorem of sci.math). 1 = 0.

    Proof: Add 1 and divide by 2.

    2. THEOREM. \pi = 0.

    Proof (Bernoulli): (-1)^2 = 1.
           2\ln(-1) = \ln((-1)^2) = \ln(1) = 0.
           i\pi = \ln(-1) = 0. [From \exp(i\pi) = -1.]
           \pi = 0.

    COROLLARY as above, proof left to reader.

    3. THEOREM. (Main Theorem of electricity) There is no alternating current.

    Proof: The voltage U as a function of time is given by the real part of
       U(t) = U_0 \exp(it\omega).
    Introduce the frequency \nu = \omega/2\pi and get
       U(t) = U_0 \exp(2\pi i \nu t)
            = U_0 (\exp(2\pi i))^{\nu t}
            = U_0 1^{\nu t}
            = U_0.
    Therefore U is constant.

    COROLLARY. 1 = 0.

    Proof: Take U_0 = 1, \omega = \pi/2. Then U(0) = 1, U(1) = i,
    so by the theorem 1 = i. Taking real parts gives the corollary.

    Klaus Pommerening
    Institut fuer Medizinische Statistik und Dokumentation
    der Johannes-Gutenberg-Universitaet
    Obere Zahlbacher Strasse 69, W-6500 Mainz, Germany

  10. admin says:

    p…@anke.imsd.uni-mainz.DE (Prof. Dr. Klaus Pommerening) writes:

    > The most elegant proofs in Mathematics usually use complex numbers. Here  
    > are three of them:

    > 1. THEOREM. -1 = 1.

    > Proof: -1 = i^2 = i \dot i = \sqrt{-1}\dot\sqrt{-1} =
    >        \sqrt{(-1)(-1)} = \sqrt{1} = 1.
    > Klaus Pommerening
    > Institut fuer Medizinische Statistik und Dokumentation
    > der Johannes-Gutenberg-Universitaet
    > Obere Zahlbacher Strasse 69, W-6500 Mainz, Germany

    do I spoil the proof if I point out that (sqrt a * sqrt b) = (sqrt(a*b)) only
    for reals.

    ——
    ste…@cellar.org (Steve Kraisler)
    The Cellar BBS – (215) 539-3043

  11. admin says:

    In article <y9H23B1w1…@cellar.org> ste…@cellar.org (Steve Kraisler) writes:
    >p…@anke.imsd.uni-mainz.DE (Prof. Dr. Klaus Pommerening) writes:

    >> The most elegant proofs in Mathematics usually use complex numbers. Here  
    >> are three of them:

    >> 1. THEOREM. -1 = 1.

    >> Proof: -1 = i^2 = i \dot i = \sqrt{-1}\dot\sqrt{-1} =
    >>        \sqrt{(-1)(-1)} = \sqrt{1} = 1.

    >do I spoil the proof if I point out that (sqrt a * sqrt b) = (sqrt(a*b)) only
    >for reals.

    Isn’t -1 a real number? :-)

    Reinhard


    Reinhard Stolle          Room #279 Willard Hall  | Nothing makes a person
    +1/303/786-4988          Boulder CO 80310        | more productive than
    sto…@cs.Colorado.EDU   USA                     | the last minute.

  12. admin says:

    The function

              f(x) = sgn(x) on |R\{0}

    is obviously differentiable and f’ = 0. It follows that f = const and hence

             -1 = f(-1) = f(1) = 1.

    That this implies 0=1 is left as an exercise to the interested reader.


        Dirk Alboth, Dept. of Mathematics, Univ. of Paderborn, Germany

  13. admin says:

    an other "proof"

    let’s have    a=b

       so   a^2 = b^2 = ab

        and   a^2 – b^2 = a^2 – ab

              (a – b)(a + b) = a(a – b)

              and then  if we divide by (a – b)   ( in fact we are not allowed to
                                                    divide by 0)

                 a + b = a

                 So if a = b = 1

                 we have   1+1=1

                 we may substract 1 from the both side and 1=0


                                                              ____
                                                            _(____)_
    ____________________________________________________ooO_(_o__o_)_Ooo_____
    Olivier Lemaitre        

  14. admin says:

    In article <1s8vp2$…@news.uni-paderborn.de> di…@uni-paderborn.de (Dirk Alboth) writes:
    >The function

    >          f(x) = sgn(x) on |R\{0}

    >is obviously differentiable and f’ = 0. It follows that f = const and hence

    >         -1 = f(-1) = f(1) = 1.

    >That this implies 0=1 is left as an exercise to the interested reader.

    >–
    >    Dirk Alboth, Dept. of Mathematics, Univ. of Paderborn, Germany

    Too easy!  Even I can see the flaw in this one… (I can see the flaw in
    most, since it’s usually a carefully concealed division by zero).

    While f(x) is differentiable, it’s NOT differentiable at 0.  f is not
    (necessarily) constant over any interval containing 0.  Therefore, f(-1)
    does not have to equal f(1).


    —–
    Buddha Buck            bmb1…@ultb.isc.rit.edu
    (insert-file ".disclaimer")
    "I’m not an actor, but I play one on TV."

  15. admin says:

    The sequence of numbers t_1, t_2, t_3, … is recursively defined by the
    equations
            t_1 = 1   and
            t_n = s_{n-1} + 2,
    where
            s_n = t_1 + … + t_n.
    From these equations we derive the closed form for t_n as follows:
            t_{n+1} – t_n = s_n – s_{n-1} = t_n,
    so
            t_{n+1} = 2 * t_n.
    So, obviously,
            t_n = 2^{n-1} * t_1 =  2^{n-1}.
    Just to be sure that we got it right, let us check:
            t_1 = 1.
    So
            2 = t_2 = s_1 + 2 = 1 + 2 = 3.
    So 2 = 3, right? And 0 = 1.

    Wim Ruitenburg

  16. admin says:

    di…@uni-paderborn.de (Dirk Alboth) writes:
    >The function
    >          f(x) = sgn(x) on |R\{0}
    >is obviously differentiable and f’ = 0. It follows that f = const and hence

    >         -1 = f(-1) = f(1) = 1.
    >That this implies 0=1 is left as an exercise to the interested reader.

        This reminds me of another possible proof that 0 = 1:

        Let c(x) be the cantor ternary function on [0,1].  Note that c(0) = 0
        and c(1) = 1; the function is nondecreasing, continuous and differentiable
        almost everywhere.  Since c(x) is flat almost everywhere, c’(x) = 0
        almost everywhere and so integrating c’(x) from 0 to 1 gives 0 but
        since the integral of c’(x) is also the net change of its antiderivative,
        the integral of c’(x) from 0 to 1 is also equal to c(1)-c(0) = 1 – 0 = 1.
        Hence 0 = 1.

        Frank Hubeny

  17. admin says:

    - Hide quoted text — Show quoted text -

    >COROLLARY (The Main Theorem of sci.math). 1 = 0.

    >Proof: Add 1 and divide by 2.
    >   U(t) = U_0 \exp(it\omega).
    >Introduce the frequency \nu = \omega/2\pi and get
    >   U(t) = U_0 \exp(2\pi i \nu t)
    >        = U_0 (\exp(2\pi i))^{\nu t}
    >        = U_0 1^{\nu t}
    >        = U_0.
    >Therefore U is constant.

    >COROLLARY. 1 = 0.

    >Proof: Take U_0 = 1, \omega = \pi/2. Then U(0) = 1, U(1) = i,
    >so by the theorem 1 = i. Taking real parts gives the corollary.
    >Here is a simple proof for proving that 1 = 0 :
    >Use exponential laws :
    >                          x^0 = 1
    >   therefore              1^0 = 1
    >           and  any number to the power 1 is the number itself:
    >                              1^1 = 1
    >                     Using base laws :
    >               if   a^2 = a^x     then
    >                      x = 2
    >                   1^1  = 1 = 1^0
    >       this means     1 = 0.
    > Do ent.

         Any suggestions to upgrade my proof are welcome!

    - Hide quoted text — Show quoted text -

    >From :Hermano rauw.

  18. admin says:

    H R Rapetsoa (hrape…@cs1.uct.ac.za) wrote:

    : >Here is a simple proof for proving that 1 = 0 :
    : >Use exponential laws :
    : >                          x^0 = 1

    : >   therefore              1^0 = 1

    : >           and  any number to the power 1 is the number itself:

    : >                              1^1 = 1

    : >                     Using base laws :

    : >               if   a^2 = a^x     then

    : >                      x = 2

    : >                   1^1  = 1 = 1^0

    : >       this means     1 = 0.
    : > Do ent.

    What is the base law?

    Henry Choy
    c…@cs.usask.ca

    Anything worth doing is worth overdoing.  - R. Heinlein
              is worth doing well. – Philip Dormer Stanhope, Earl of Chesterfield

  19. admin says:

    Here is another one:

    0 = (1-1)+(1-1)+(1-1)+….
      =  1 + (-1+1) + (-1+1) + (-1+1) + ….    (shifting of the paratheses!)
      =  1 + 0 + 0 + 0 + ….
      =  1

    This should be a good example to remember
    for those who are tempted to shift paratheses in
    infinite sums…

    Anyway, the thing to remember with 0=1 in a ring is that it implies
    that the ring has exactly one element.

    ————————————————————-
    GH.

  20. admin says:

    Or working backwards:

    There’s a story that A. N. Whitehead mentioned in a lecture that a false
    statement implies every statement.  One of his students was dubious, and
    said "Suppose 4 = 3, now prove you’re the Pope".  Whitehead said "If
    4 = 3, then 3 = 2, and if 3 = 2, then 2 = 1.  It’s well known that the
    Pope and I are two, therefore …"

    Jonathan Ryshpan                <j…@halsp.hitachi.com>

            ===============> I write for myself ONLY. <===============

  21. admin says:

    there are no proofs that 0=1. since it’s not true.  These demonstrations of
    stupidity are not proofs.

        mn…@hotcity.com

  22. admin says:

    In article <jon.747101519@amito> j…@halsp.hitachi.com (Jonathan Ryshpan) writes:
    >Or working backwards:

    >There’s a story that A. N. Whitehead mentioned in a lecture that a false
    >statement implies every statement.  One of his students was dubious, and
    >said "Suppose 4 = 3, now prove you’re the Pope".  Whitehead said "If
    >4 = 3, then 3 = 2, and if 3 = 2, then 2 = 1.  It’s well known that the
    >Pope and I are two, therefore …"

    >Jonathan Ryshpan                <j…@halsp.hitachi.com>

    >    ===============> I write for myself ONLY. <===============

    Reminds me of a similar logical tangle: Prove that Napolean had an
    infinite number of arms.

    a. Before going into battle, Napolean was forewarned.
    b. To be forewarned is to be forearmed.
    c. Four arms is an odd number for a human.
    d. Four is an even number.
    e. What number is both odd and even? Infinity.
    f. Therefore, Napolean had an infinite number of arms. qed.

    (This also implies that Napolean was a poor tactician. If
    he had an infinite number of arms, he should have certainly
    have been adequately armed so as to have defeated Wellington
    at Waterloo. Hence, his defeat must have been the result of
    poor tactics.)

    ——————————————————————————
    Why should I mourn                                                        
    The vanished power of the usual reign                                    
      –T.S. Eliot, Ash-Wednesday                                            
    ……………………………………………………………………
    s.w. marlatt, <><  &  *(:-)               Prov. 25.2
    University of Colorado:                   marl…@spot.Colorado.edu  492-3939
    National Center for Atmospheric Research: marl…@neit.cgd.ucar.edu  497-1669
    ——————————————————————————

  23. admin says:

    I heard that as a proof that all horses have an infinite number of legs: two
    forelegs and two hindlegs, which is six legs, an odd number for a horse.


    James A. Foster                           fos…@cs.uidaho.edu
    Universty of Idaho                        Dept. of Computer Science

  24. admin says:

    Since this (old) thread has been revived I thought I might jump on the
    bandwagon and offer the following proof that 1 = 0.  This is dedicated to
    all those people who believe that the reals are countable.

    Theorem.  1 = 0.
    Proof. (Assuming countability of the reals.)  Since the reals are
           countable, thus the constant function 1 on the real numbers is
           equal almost everywhere to the zero function.  Integrating on
           [0,1] yields 1 = 0.


    ——————————————————————————
    | Kin Yan Chung (kin…@math.princeton.edu) |                                |
    |     Aussie in (self-imposed) exile        |    .sig under construction     |
    ——————————————————————————







Place your comment

You must be logged in to post a comment.