On Sun, 29 Jul 2001, Do Hoang Son wrote: ........> > It returns: > -m2*p1\-p1\*p2\-m2*ONE*m1-p2\*m1 > > The correct one should be: > m2*p1\-p1\*p2\+m2*ONE*m1+p2\*m1 ^^^^^ Sorry, it shold be m2*p1\-p1\*p2\+m2*ONE*m1 - p2\*m1 ^^^^^ So*n.