  Gr\"atzer and Lakser asked in the 1971 {\sl Transactions of the American
Mathematical Society} if the pseudocomplemented distributive lattices in the
amalgamation class of the subvariety generated by ${\bf 2}^n\oplus{\bf 1}$ can
be characterized by the property of not having a $*$-homomorphism onto ${\bf
2}^i\oplus{\bf 1}$ for $1<i<n$.
  In this article, this question is answered.
  If you want to know the answer, you will have to read it (or skip to the last
section).
