1. (ASL) ["Structured Algebraic SpecificATions: A Kernel Language", M. Wirsing, Theor Comput Sci 42, pp.123-249, Elsevier 1986]. 2. (ASF) A language for equATional specificATion of abstract dATa types. ["Algebraic SpecificATion", J.A. Bergstra et al, A-W 1989]. (1995-12-13)