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Submitted by : (unknown) at: 2007-11-17T22:24:55-08:00 (9 years ago)
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axiom
UTSx := UTS(FRAC INT,x,0)

\label{eq1}\hbox{\axiomType{UnivariateTaylorSeries}\ } (\hbox{\axiomType{Fraction}\ } (\hbox{\axiomType{Integer}\ }) , x , 0)(1)
Type: Type
axiom
monx2 := monomial(1,2)$UTSx

\label{eq2}x^2(2)
Type: UnivariateTaylorSeries?(Fraction(Integer),x,0)
axiom
sqrt(monx2)

\label{eq3}x(3)
Type: UnivariateTaylorSeries?(Fraction(Integer),x,0)

The last line should of course be x and not 1. Clearly, sqrt() shifts the coefficients of the result such that the leading term is always O(1).

Fix by Igor Khavkine --kratt6, Fri, 27 Oct 2006 03:02:19 -0500 reply
I'm forwarding this fix proposed by Igor himself, lest it is lost in the archives.

The relevant message in axiom-math is

http://lists.gnu.org/archive/html/axiom-math/2006-08/msg00025.html

For simplicity, here is the fix:

  diff -ur axiom-20050901/src/algebra/sttaylor.spad.pamphlet axiom-20050901.new/src/algebra/sttaylor.spad.pamphlet
  --- axiom-20050901/src/algebra/sttaylor.spad.pamphlet 2005-01-30 07:03:10.000000000 -0500
  +++ axiom-20050901.new/src/algebra/sttaylor.spad.pamphlet     2006-08-21 15:49:25.000000000 -0400
  @@ -448,6 +448,9 @@

             RATPOWERS => co**rn * YS(powerrn(rn,(invCo :: A) * x,#1))
             error "** rational power of coefficient undefined"
  +        zeropref : ST A := new(ord::I::NNI,0::A)$LA :: ST A
  +        concat(zeropref, power)
  +

       if A has Field then
         mapdiv(x,y) == delay

If somebody could complete the documentation as outlined in

http://lists.gnu.org/archive/html/axiom-developer/2006-08/msg00486.html

that would be great.

Finally, I have to confess that it is very likely myself who introduced this bug, while fixing #63

Martin

fix by Igor Khavkine --kratt6, Fri, 27 Oct 2006 03:03:15 -0500 reply
Status: open => fix proposed

Here is the documented patch. (Documentation is partially due to Waldek Hebisch)

powern.patch

Martin

Fixed in OpenAxiom




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