HILBERT _ _ _ _ _ _ _ _ _ _ _ _ operator
<square\_size> :- a positive integer.
<expr> :- an algebraic expression.
hilbertcomputes the square hilbert matrix of dimension <square\_size>.
This is the symmetric matrix in which the (i,j)'th entry is 1/(i+j-<expr>).
hilbert(3,y+x); [ - 1 - 1 - 1 ] [----------- ----------- -----------] [ x + y - 2 x + y - 3 x + y - 4 ] [ ] [ - 1 - 1 - 1 ] [----------- ----------- -----------] [ x + y - 3 x + y - 4 x + y - 5 ] [ ] [ - 1 - 1 - 1 ] [----------- ----------- -----------] [ x + y - 4 x + y - 5 x + y - 6 ]