

Semantic Foundations for
Heterogeneous Systems
Roberto
Passerone
UC Berkeley & Cadence
Monday, February
23rd,
2004, 2pm  3pm
540A/B Cory Hall (D.O.P. Center Classroom)
Dissertation talk

Abstract
We propose the
framework of Agent Algebra as a foundation for the study of
heterogeneous systems. Different models of computation can be
expressed in terms of a common algebraic structure that includes the
usual operations of scoping, instantiation and parallel composition and
a relation of refinement. The models can then be related by structure
preserving maps. In particular, we study the concept of conservative
approximation which preserves refinement verification results from
abstract to concrete models. We also show that conservative
approximations are more general than the established notion of abstract
interpretation.
The common algebraic structure is also used to study techniques that
can
be applied to all models of computation. In this talk we focus on a
characterization of the refinement relationship in terms of
substitutability and compatibility, and provide the necessary and
sufficient conditions for the existence for each component of a most
general environment, called "mirror", that characterizes the refinement
order. The mirror is then used to solve the problem of deriving a local
specification for a component given a global specification and a
context. We show under which conditions the problem admits an algebraic
solution in closed form.
