[CZT-Users] Typechecker: cyclic definition of schema's

[nelis <nel...@cs...>]

Dear,

I want to define something like:

\begin{schema}{SUBSTRUCTURE}\\
 components : \power COMPONENT \\
 connectors : \power CONNECTORS \\
 links : \power LINKS \\
 interfaceMappings : \power INTERFACEMAPPING
\end{schema}

\begin{schema}{COMPONENT}\\
 identifier : IDENTIFIER \\
 description : TEXT \\
 interfaces : \power INTERFACE \\
 subStructure : SUBSTRUCTURE
\end{schema}

But I get the follow problem: the typechecker seems unable to handle a 
schema definition that relies on a schema that is specified further in 
the document. Like in the example, Substructure can not rely on the 
definition of component.

At first sight this might seem as a minor constraint, but for my formal 
specification I fast run into problems. For example, a component can 
have a substructure that exists of components and connectors. Thus I 
need to define substructure in terms of components, and a component in 
terms of a substructure. Why does the typechecker not support such 
cases? As far as I understood, schema's are independent 'entities' in 
the Z description, so I would expect this to be possible. Does anyone 
have suggestions on how to circumvent this problem?

Kind regards,
Nelis