  Given stable rational matrix functions $G$ and $K$, a procedure is presented
to compute a stable rational matrix solution $X$ to the Leech problem
associated with $G$ and $K$, that is, $G(z)X(z)=K(z)$ and $\sup_{|z|\leq
1}\|X(z)\|\leq 1$. The solution is given in the form of a state space
realization, where the matrices involved in this realization are computed from
state space realizations of the data functions $G$ and $K$.
