On embeddings of full amalgamated free product C*-algebras

We examine the question of when the -homomorphism of full amalgamated free product C-algebras \lambda: A D B --> A’ *{D’} B’, arising from compatible inclusions of C-algebras A in A’, B in B’ and D in D’, is an embedding. Results giving sufficient conditions for \lambda to be injective, as well of classes of examples where \lambda fails to be injective, are obtained. As an application, we give necessary and sufficient condition for the full amalgamated free product of finite dimensional C*-algebras to be residually finite dimensional.