SEMANTICS OF MODEL COMPOSITION IN HYBRID LANGUAGES
Gábor Fábián, D.A. van Beek, J.E. Rooda · 1998
The increasing complexity of hybrid models requires a mathematically sound language semantics that allows reasoning about model behaviour and supports development of robust models. Model composition in hybrid languages is realised by connecting continuous variables of sub-models. It is important to define the precise semantics of connections. Improperly defined connection semantics can a) introduce undesirable nondeterminism and b) lead to undesirable semantics of conditional language constructs. In this article four different connection semantics are examined. Three of them impose strong restrictions on the modelling style or lead to less robust models. In the hybrid c language the fourth possibility is chosen: a connection represents an algebraic equation. In combination with the initial state calculation mechanism, and the use of local variables, this results in robust and elegant composition semantics. 1. Introduction Most hybrid languages support hierarchical models. Since many ...