  The Yoneda algebra of a Koszul algebra or a D-Koszul algebra is Koszul. K_2
algebras are a natural generalization of Koszul algebras, and one would hope
that the Yoneda algebra of a K_2 algebra would be another K_2 algebra. We show
that this is not necessarily the case by constructing a monomial K_2 algebra
for which the corresponding Yoneda algebra is not K_2.
