Historical Notes

The APERO facilities have been defined and implemented by Charles Pecheur in the context of his doctorate thesis. The syntax extensions find their origin in the work of G. Scollo back in 1986, while the principle of virtual libraries was settled in an early prototype called VLib.

This work has been supported by the Euro-Canadian project EUCALYPTUS. In this framework, the APERO tools have been integrated in a LOTOS tool set, together with CAESAR/ALDEBARAN (model generation and verification, Verimag, Grenoble), ELUDO (interactive simulator, U. Ottawa) and TETRA (test validation, U. Montreal).


The APERO data type pre-processors seek to offer a technical solution helping the specification of common data structures in LOTOS while keeping compatibility with the standard language, and therefore with existing tools. The proposed solution is based on two complementary mechanisms: Both mechanisms are supported by their respective tools: In particular, syntax extensions can be translated into instances of virtual library types.

Both functions rely on a generic text transformation algorithm and externally specified transformation rules. These rules are defined in the APERO language, which is a pattern-based formalism derived from a macro notation used in the Scheme language. On one hand, this facilitates the modification and/or extension of the provided extensions and library types. On the other hand, this allows several alternative transformation rules for the same set of facilities, where the translated specification is tuned for several environments (human reading, compiler, simulator).


The APERO tools are described in

Ch. Pecheur, ``Improving the Specification of Data Types in LOTOS'', thèse de doctorat, Université de Liège. (Abstract)

VLib, the preliminary prototype of APERO-LIB, is presented in

Ch. Pecheur, ``VLib: infinite virtual libraries for LOTOS'', Protocol Specification, Testing and Verification XIII, North Holland, Amsterdam (1993), 29-44. (Full text)

For further information, please contact either Charles Pecheur (pecheur@ptolemy.arc.nasa.gov) or Guy Leduc (leduc@montefiore.ulg.ac.be).



The APERO tools are now available free of charge. If you wish to get a copy of this, please read the LICENSE Agreement and fill in the attached register form.

For more information, please contact:
Guy Leduc
Université de Liège
Institut Montefiore (B28)
B-4000 Liège