Function: polsylvestermatrix
Section: polynomials
C-Name: sylvestermatrix
Prototype: GG
Help: polsylvestermatrix(x,y): forms the sylvester matrix attached to the
 two polynomials x and y. Warning: the polynomial coefficients are in
 columns, not in rows.
Doc: forms the Sylvester matrix
 corresponding to the two polynomials $x$ and $y$, where the coefficients of
 the polynomials are put in the columns of the matrix (which is the natural
 direction for solving equations afterwards). The use of this matrix can be
 essential when dealing with polynomials with inexact entries, since
 polynomial Euclidean division doesn't make much sense in this case.
