-----Richard Fateman wrote: -----
>The definite integration program is really a
>hack. it uses numbers like 10000000 to approximate
>infinity, I guess. It also uses floating point numbers.
Another test of subres & spmod using indefinite integration
(%i14) ratsimp(diff(integrate(1/(1+x^5),x),x)), gcd : red;
(%o14)
((30*sqrt(5)+150)*x^3-60*sqrt(5)*x^2-60*sqrt(5)*x+30*sqrt(5)+350)/(800*x^5+800)
<-- wrong
(%i15) ratsimp(diff(integrate(1/(1+x^5),x),x)), gcd : subres;
(%o15)
((30*sqrt(5)+150)*x^3-60*sqrt(5)*x^2-60*sqrt(5)*x+30*sqrt(5)+350)/(800*x^5+800)
<-- wrong
(%i17) ratsimp(diff(integrate(1/(1+x^5),x),x)), gcd : spmod;
(%o17) 1/(x^5+1)
<-- OK
(%i18) ratsimp(diff(integrate(1/(1+x^5),x),x)), gcd : ez;
<-- takes a long time...
Barton