Part I deals with basic specifications--first many-sorted, then subsorted; Part II provides structured specifications; Part III summarizes so-called architectural specifications, which, in contrast to the foregoing specifications, prescribe the separate development of composable, reusable implementation units; and finally Part IV considers libraries of definitions. For each kind of specification, the main underlying semantic concepts are summarized, then the abstract syntax of the language constructs is given and its semantics is described informally.
An Appendix provides a complete grammar for the abstract syntax of the language. The sort and constructor symbols used in the abstract syntax are reasonably suggestive of their intended interpretation, so reading this grammar may be the easiest way to get a quick overview of the language.
N.B. The constructor symbols of the abstract syntax are generally not intended for use as key-words, nor is the order of components of constructs necessarily that to be used in concrete syntax. (The concrete syntax for CASL is still being discussed [Mos97a].)
Two (equivalent) grammars for abstract syntax are provided: the first merely collects together the productions given throughout Parts I-IV, in the order in which they appear in the text; the second is more compact, and given in a more top-down order
A Bibliography provides references to related documents.
Another Appendix lists the main changes that have been made to the CASL Proposed Design.
A final Appendix lists the points where further discussion is needed to resolve various questions about the Proposed Design.
The (rudimentary) Index may facilitate locating the places where terminology is explained.