`prim', `cont'
--------------

prim(POLY[,V])
     :: Primitive part of POLY.

cont(POLY[,V])
     :: Content of POLY.

RETURN POLY
     polynomial over the rationals

V
     indeterminate

   * The primitive part and the content of a polynomial POLY with
     respect to its main variable (V if specified).

     [0] E=(y-z)*(x+y)*(x-z)*(2*x-y);
     (2*y-2*z)*x^3+(y^2-3*z*y+2*z^2)*x^2+(-y^3+z^2*y)*x+z*y^3-z^2*y^2
     [1] prim(E);
     2*x^3+(y-2*z)*x^2+(-y^2-z*y)*x+z*y^2
     [2] cont(E);
     y-z
     [3] prim(E,z);
     (y-z)*x-z*y+z^2

References
     *Note `var': var, *Note `ord': ord.

