  We compute the structure relations in special A_\infty-bialgebras whose
operations are limited to those defining the underlying A_\infty-(co)algebra
substructure. Such bialgebras appear as the homology of certain loop spaces.
Whereas structure relations in general A_\infty-bialgebras depend upon the
combinatorics of permutahedra, only Stasheff's associahedra are required here.
