Problem with x variable in potential



Hello all!

I use Maxima 5.17.0 and I am new user.

I encountered this problem:

(%i1) load(vect);
(%o1)           /usr/share/maxima/5.17.0/share/vector/vect.mac
(%i2) potential([y*z,x*z,x*y],[x,y,z]);
+Non-variable 2nd argument to diff:
       d                 d                 d
[y z - -- (x y z), x z - -- (x y z), x y - -- (x y z)]
       dx                dy                dz
#0: ev_diff(x=[y*z-'diff(x*y*z,x,1),x*z-'diff(x*y*z,y,1),x*y-'diff(x*y*z,z,1)])
#1: potential1(gr=[y*z,x*z,x*y])(vect.mac line 353)
 -- an error.  To debug this try debugmode(true);

But if I rename the x variable, I get the answer:

(%i3) potential([y*z,x1*z,x1*y],[x1,y,z]);
(%o3)                               x1 y z

Did I do something wrong? Thanks for any help.

Alexandros