This chapter indicates the abstract and concrete syntax of the constructs of structured specifications, and describes their intended interpretation, extending what was provided for basic (many-sorted and subsorted) specifications in Part I.
The summary below indicates when structured specifications are well-formed, and how their signatures and classes of models are determined by those of their component specifications. The interpretation is essentially based on model classes--a "flattening" reduction to sets of sentences is not possible, in general (due to the presence of constructs such as hiding and freeness).
A structured specification can only be well-formed when all its component specifications are well-formed.