returns the (weighted) degree of
the initial term of a polynomial or a vector;
the weights are the weights used for the first block of the ring ordering.
Note:
ord(0) is -1.
In a global degree ordering ord is the same as deg.
Example:
ring r=7,(x,y),wp(2,3);
ord(0);
==> -1
poly f=x2+y3; // weight on y is 3
ord(f),deg(f);
==> 9 9
ring R=7,(x,y),ws(2,3);
poly f=x2+y3;
ord(f),deg(f);
==> 4 9
vector v=[x2,y];
ord(v),deg(v);
==> 3 4