Abstract. Heterogeneous specification becomes more and more important because complex systems are often specified using multiple viewpoints, involving multiple formalisms. Moreover, a formal software development process may lead to a change of formalism during the development. However, current research in integrated formal methods only deals with ad-hoc integrations of different formalisms. The heterogeneous tool set (Hets) is a parsing, static analysis and proof management tool combining various such tools for individual specification languages, thus providing a tool for heterogeneous multi-logic specification. Hets is based on a graph of logics and languages (formalized as so-called institutions), their tools, and their translations. This provides a clean semantics of heterogeneous specification, as well as a corresponding proof calculus. For proof management, the calculus of development graphs (known from other large-scale proof management systems) has been adapted to heterogeneous specification. Development graphs provide an overview of the (heterogeneous) specification module hierarchy and the current proof state, and thus may be used for monitoring the overall correctness of a heterogeneous development. 1

The UniForM Workbench supports combination of Formal Methods (on a solid logical foundation), provides tools for the development of hybrid, real-time or reactive systems, transformation, verification, validation and testing. Moreover, it...

For the recently developed specification language Casl, there exist two different kinds of proof support: while HOL-Casl has its strength in proofs about specifications in-the-small, Maya has been designed for management of proofs in (Casl) specifications in-the-large, within an evolutionary formal software development process involving changes of specifications. In this work, we discuss our integration of HOL-Casl and Maya into a powerful system providing tool support for Casl, which will also serve as a basis for the integration of further proof tools.

CASL, the common algebraic specification language, has been developed as a language that subsumes many previous algebraic specification frameworks and also provides tool interoperability. CASL is a complex language with a complete formal semantics. It is therefore a challenge to build good tools for CASL. In this work, we present and discuss the Bremen HOL-CASL system, which provides parsing, static checking, conversion to LaTeX and theorem proving for CASL specifications. To make tool construction manageable, we have followed some guidelines: re-use of existing tools, interoperability of tools developed at different sites, and construction of generic tools that can be used for several languages. We describe the structure of and the experiences with our tool and discuss how the guidelines work in practice.

We present an approach to mathematical assistants which uses readable, executable proof scripts as the central language for interaction. We examine an implementation that combines the Isar language, the Isabelle theorem prover and the IsaPlanner proof planner. We argue that this synergy provides a flexible environment for the exploration, certification, and presentation of mathematical proof.

We present a family of tools for program development and verification, comprising the transformation system TAS and the theorem proving interface IsaWin. Both are based on the theorem prover Isabelle [6], which is used as a generic logical framework here. A graphical user interface, based on the principle of direct manipulation, allows the user to interact with the tool without having to concern himself with the details of the representation within the theorem prover, leaving him to concentrate on the main design decisions of program development or theorem proving. The tools form an integrated system for formal program development, in which TAS is used for transformational program development, and IsaWin for discharging the incurred proof obligations. However, both tools can be used separately as well. Further, the tools are generic over the formal method employed. In this extended abstract, we will first give a brief overview over TAS and IsaWin. Since TAS and I...

We show how to write an abstract interface corresponding to Meseguer's concept of general logic in Haskell. Based on this, we develop a tool set for structured specifications that are based on such logics, consisting of a parser, a static analysis and a theorem prover. While with Standard ML functors, it is only possible to be generic over an arbitrary logic, we show how true heterogeneity (i.e. for specification involving simultaneously different logics) is achieved in Haskell. Concerning genericity, it is folklore that Standard ML functors can be simulated in Haskell using multiparameter type classes with functional dependencies. On top of this, heterogeneity is achieved using existential and dynamic types.

We describe the design and prototype implementation of a combination of theorem prover interface technologies. On one side, we take from Proof General the idea of a prover-independent interaction language and its proposed implementation within the PG Kit middleware architecture. On the other side, we take from IsaWin a sophisticated graphical metaphor using direct manipulation for developing proofs. We believe that the resulting system will provide a powerful, robust and generic environment for developing proofs within interactive proof assistants that also opens the way for studying and implementing new mechanisms for managing interactive proof development. 1

This paper describes the several user-interface features for interactive theorem provers. Many of these features mimic functionality that already exists, and have great utility, in modern interactive development environments (IDEs). A formal kind theoretic model of a user’s context is also presented. This model is used to formally describe the structure, behavior, and customization of the features. The functionality presented include browsers for basic mathematical constructs (declarations, theories, types, proofs, etc.), quick access to constructs definitions and uses (a short-cut sidebar, menus, or implicit hyperlinks), built-in contextual help, contextand type-aware completion and visual representation (expanding and collapsing structured elements of specifications, proof terms, and sequents), the graphical representation of language elements, and a user-extensible, type-aware pretty-printer. Research opportunities in interface design based upon the formal model are also identified and discussed. These features have been added to the PVS theorem prover as a proof-of-concept and will be available in its next major release. 1

This paper describes how proof texts are constructed and edited in the Proof General Kit framework. Proof texts are the central object of development within our framework and we want to allow flexible ways to construct them, both explicitly via text editing and implicitly by graphical manipulation or meta-manipulation. To this end, the framework allows for user-oriented display components, connected to provers via a central broker component. The display components and the broker exchange messages in a format specified by the PGIP display protocol, which facilitates parsing, editing and proving of proof texts. The design of this part of the framework is new; the remainder of the framework, which connects the prover components to the broker, is based more closely on refining work of the previous Proof General project, and was described in [4].