  In this article, we derive some identities for multilateral basic
hypergeometric series associated to the root system A_n. First, we apply
Ismail's argument to an A_n q-binomial theorem of Milne and derive a new A_n
generalization of Ramanujan's 1-psi-1 summation theorem. From this new A_n
1-psi-1 summation and from an A_n 1-psi-1 summation of Gustafson we deduce two
lemmas for deriving simple A_n generalizations of bilateral basic
hypergeometric series identities. These lemmas are closely related to the
Macdonald identities for A_n. As samples for possible applications of these
lemmas, we provide several A_n extensions of Bailey's 2-psi-2 transformations,
and several A_n extensions of a particular 2-psi-2 summation.
