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P9503   J.A. Bergstra & A. Ponse
        "Frame-based process logics"


We consider frames that can be defined by polynomials over states and
transitions. States are elements from the natural numbers with pairing, and
(state-)transitions are labeled with actions from some finite set.
We study a connection with process algebra: pointing a frame by
distinguishing either two states that function as a root and a tail,
respectively, implements a terminating process. Only selecting a root can
be used to model a non-terminating process.
This implies that frame properties can be investigated with process
algebraic means.

Providing further structure on frames by inserting propositions at the
states, gives a basic ``framework" for Floyd Hoare logic, or a modal logic
with modalities "[]a" for all actions "a" considered.


This paper will be published in: Modal Logic and Process algebra, Alban
Ponse, Yde Venema and Maarten de Rijke (eds.), CSLI publications, to appear.