On 12/14/2012 08:14 AM, Dmitry Shkirmanov wrote:
> Maxima 5.29.1 http://maxima.sourceforge.net
> using Lisp SBCL 1.0.40.0.debian
> Distributed under the GNU Public License. See the file COPYING.
> Dedicated to the memory of William Schelter.
> The function bug_report() provides bug reporting information.
> (%i1) g(mu,nu):= if (mu=0 and nu =0) then 1
> elseif (mu=1 and nu =1) then -1
> elseif (mu=2 and nu =2) then -1
> elseif (mu=3 and nu =3) then -1
> elseif ( mu#nu and ((mu=1 or mu=2 or mu=3 or mu=0)and(nu=1
> or nu=2 or nu=3 or nu=0)) ) then 0
> else 'g(mu,nu)$
>
> (%i2) expr: g(i,j);
> (%o2) g(i, j)
> (%i3) expr: subst([i=1, j=2], expr);
> (%o3) g(1, 2)
> (%i4) ev(expr);
> (%o4) g(1, 2)
> (%i5) g(1,2);
> (%o5) 0
> (%i6)
>
> So, why in the (%o4) maxima returns g(1,2) instead of 0?
because you should add the keyword "nouns" to make nouns turn into
verbs. Try
ev(expr,nouns);
Regards,
Jaime