[PURRS-devel] Strange behavior of numer_denom
Roberto Bagnara
bagnara at cs.unipr.it
Mon Jun 30 10:07:36 CEST 2003
Hi there,
in the following session, numer_denom is computed several times
on the same expression (using the up-arrow history recall mechanism):
$ ./ginsh
ginsh - GiNaC Interactive Shell (GiNaC V1.1.1)
__, _______ Copyright (C) 1999-2003 Johannes Gutenberg University Mainz,
(__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY.
._) i N a C | You are welcome to redistribute it under certain conditions.
<-------------' For details type `warranty;'.
Type ?? for a list of help topics.
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{1264*d,1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{1264*d,1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{1264*d,1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{1264*d,1264}
>
numer_denom((-(4/79*I)*(-1/8+(1/8*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))*sqrt(79))*d-(3/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)+(3/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(-3/32-(3/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(3/32-(3/32*I)*sqrt(79))*sqrt(79)+(-(4/79*I)*(-1/32-(1/32*I)*sqrt(79))*sqrt(79)-(4/79*I)*(1/32-(1/32*I)*sqrt(79))*sqrt(79)+(4/79*I)*(1/8-(1/8*I)*sqrt(79))^2*sqrt(79)-(4/79*I)*(1/8+(1/8*I)*sqrt(79))^2*sqrt(79))*c-3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))^3+3/4*(-(1/8-(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(1/8-(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8-(1/8*I)*sqrt(79))-3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))+3/4*((1/8+(1/8*I)*sqrt(79))^2-(1/4*I)*sqrt(79)+(-1/8+(1/8*I)*sqrt(79))*(1/8+(1/8*I)*sqrt(79)))^(-1)*(1/8+(1/8*I)*sqrt(79))^3);
{-1264*d,-1264}
>
There are two problems here: (1) the numerator and denominator returned
are trivially not coprime; and (2) numer_denom does not behave like a
mathematical function. With the same input, it produces the sequence
of answers
{-1264*d,-1264}
{-1264*d,-1264}
{1264*d,1264}
{-1264*d,-1264}
{-1264*d,-1264}
{1264*d,1264}
{-1264*d,-1264}
{1264*d,1264}
{1264*d,1264}
{-1264*d,-1264}
All the best
Roberto
--
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it
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