Raymond Toy <toy@rtp.ericsson.se> writes:
(C2) ?limitp:true;
(D2) TRUE
> Wolfgang> (C4) asksign(log(x));
> Wolfgang> Is x positive or negative?
>
> Wolfgang> neg;
> Wolfgang> (D4) PNZ
>
> Shouldn't maxima say something else since the sign of a complex number
> isn't well defined?
I should think that PNZ is just the sign of complete agnosticism while
any other result implies of course that the expression in question is
real (cf. the description of `sign' in "Definitions for Operators").
So the point is that PNZ is always a correct result ;-) The
disadvantage of this is that an opportunity for actually determining a
sign might be missed: Try for example `asksign(exp(x+%i*y))' with both
settings of `?limitp'.
Wolfgang
--
wjenkner@inode.at