  We investigate the weak Hopf algebras of Li based on $U_q[sl_n]$ and
Sweedler's finite dimensional example. We give weak Hopf algebra isomorphisms
between the weak generalisations of $U_q[sl_n]$ which are ``upgraded''
automorphisms of $U_q[sl_n]$ and hence give a classification of these
structures as weak Hopf algebras. We also show how to decompose these examples
into a direct sum which leads to unexpected isomorphisms between their
algebraic structure.
