History and dialects

Genuine AltaRica.
The AltaRica language has been designed at the end of 90s in PhD thesis of G. Point. Concepts and semantics were designed during a collaboration between two laboratories of Bordeaux, the LaBRI and the LADS, IXI (an engineering company) and ELF Aquitaine (today, Total). This collaboration has been called the AltaRica1 project. After one year and half, the project interested several others industrial partners2 among which Dassault Aviation and ONERA played an important role in the promotion of AltaRica. During this former period, the design and formal semantics of AltaRica language have been published several times in both computer science and safety assessment domains.

AltaRica Data-Flow.
The constraint-based semantics of the AltaRica language requires implementation of static analysis algorithm and a constraint solver. When developing tools for the analysis of AltaRica models, these requirements are costly in terms of development effort and also in terms of performance if static analysis does not success to eliminate constraints. In 2002, in order to ease the development of tools, ARboost Technologies get round these semantic obstacles using a restricted version of the genuine language. This dialect was called Data-Flow because it enforces an orientation of flows and forbids loops in dependency-graph of variables. The drift was both semantic and syntactical. In absence of formal semantics, it was difficult to evaluate the compatibility of Data-Flow with AltaRica.

In the meantime, Dassault Aviation implemented its own restriction on the AltaRica language supported by Cecilia-OCAS workbench. Computations made within this tools could be delegated to ARboost tools and thus, Cecilia-OCS also generated Data-Flow models.

Extensions of AltaRica.
In 2005, AltaRica language has been chosen by members of Persee project as the formalism to model systems. AltaRica was not usable as is. New concepts were introduced without changing the semantics of the language. These concepts are essentially syntactic sugar that is preprocessed by the tools. Among extension there was abstract data types, statically bounded arrays and structures. Structures were also introduced in Cecilia-OCAS with, however, some additional attributes related to orientation of data-flows.

Since 2007, Data-Flow has been relabelled Guarded Transition Systems (GTS) and continued to drift from both syntactical and semantic points of view from AltaRica.


1. The project name stemmed from a joke on a software created by ELF Aquitaine : Moca-RP. An urban legend tells that capitalized letters, A and R, were chosen in honour to former project leader. Actually, in minutes of AltaRica working group, G. Point wanted to give the project name the same look than LaTeX he just started to use.
2. Between 1996 and 2003, partners of AltaRica project were: IXI, Dassault Aviation, ELF EP, Schneider Electric, Renault, IPSN, Thomson Detexis, Total-Fina-Elf, France Telecom, Thales Airborne Systems, LaBRI, IRCCyN and ONERA.