A Meta-Model for the Isabelle API

International audienceWe represent a theory of (a fragment of) Isabelle/HOL inIsabelle/HOL. The purpose of this exercise is to write packages fordomain-specific specifications such as class models, B-machines, ...,and generally speaking, any domain-specific languages whoseabstract syntax can be defined by a HOL "datatype". On this basis, theIsabelle code-generator can then be used to generate code for globalcontext transformations as well as tactic code.Consequently the package is geared towards parsing, printing and code-generation to the Isabelle API.It is at the moment not sufficiently rich for doing meta theory on Isabelle itself. Extensions in this direction are possible though.Moreover, the chosen fragment is fairly rudimentary. However it should be easily adapted to one's needs if a package is written on top of it.The supported API contains types, terms, transformation ofglobal context like definitions and data-type declarations as wellas infrastructure for Isar-setups.This theory is drawn from the Featherweight OCL project where it is used to construct a package for object-oriented data-type theoriesgenerated from UML class diagrams. The Featherweight OCL, for example, allows for both the direct execution of compiled tactic code by the Isabelle APIas well as the generation of ".thy"-files for debugging purposes.Gained experience from this project shows that the compiled code is sufficientlyefficient for practical purposes while being based on a formal "model"on which properties of the package can be proven such as termination of certaintransformations, correctness, etc