  In our paper [Markl, Shnider: Drinfel'd Algebra Deformations and the
Associahedra, IMRN 1994, no. 4, 169-176] we announced a construction of a
cohomology controlling deformations of quasi-coassociative (or Drinfel'd)
bialgebras. The full version of the paper will appear as [Markl, Shnider:
Drinfel'd Algebra Deformations, Homotopy Comodules and the Associahedra] in
Trans. Amer. Math. Soc. The construction in the paper was based on very
explicit arguments using deep combinatorial properties of the associahedra. The
present paper gives an alternative, general nonsense approach to the
construction. So, we just prove the existence of such a cohomology without
explicitly constructing it. This should be compared with the two approaches to
the cohomology of associative algebras: we either describe explicitly the
Hochschild complex and say "Behold! this is the cohomology" or we prove the
existence of a projective resolution and define the cohomology as the derived
functor.
