hgfred amusement



Am Mittwoch, den 03.03.2010, 14:23 -0600 schrieb Barton Willis:
> (%i2) hgfred([1/2,1],[3/2],x^2);
> Is  x  zero or nonzero?zero;
> (%o2) atanh(x)/x
> 
> (%i3) hgfred([1/2,1],[3/2],x^2);
> Is  x  zero or nonzero?nonzero;
> (%o3) log((x+1)/(1-x))/(2*x)

Hello Barton,

a nice example of one of the problems with asksign and hgfred. This
error is caused in the routine trig-log-3-exec. The routine tries to
distinguish between positive and negative arguments, but does not take
into account the case positive or zero.

Dieter Kaiser