Amalgamation in CASL via Enriched Signatures

We construct a representation of the institution of the algebraic specification language Casl in an institution called enriched Casl. Enriched Casl satisfies the amalgamation property, which fails in the Casl institution, as well as its converse. Thus, the previously suggested institution-independent semantics of architectural specifications is actually applicable to Casl. Moreover, a variety of results for institutions with amalgamation, such as computation of normal forms and theorem proving for structured specifications, can now be used for Casl.