  A class of indecomposable representations of U_q(sl_n) is considered for q an
even root of unity (q^h = -1) exhibiting a similar structure as (height h)
indecomposable lowest weight Kac-Moody modules associated with a chiral
conformal field theory. In particular, U_q(sl_n) counterparts of the
Bernard-Felder BRS operators are constructed for n=2,3. For n=2 a pair of dual
d_2(h) = h dimensional U_q(sl_2) modules gives rise to a 2h-dimensional
indecomposable representation including those studied earlier in the context of
tensor product expansions of irreducible representations. For n=3 the interplay
between the Poincare'-Birkhoff-Witt and (Lusztig) canonical bases is exploited
in the study of d_3(h) = h(h+1)(2h+1)/6 dimensional indecomposable modules and
of the corresponding intertwiners.
