Developed examples of traces for hybrid
systems
Wide range of levels of abstraction: Continuous time
to pre-post conditions
These examples are forcing us to
generalize the framework
More flexible signatures (a.k.a.
interfaces)
Refinements that change interfaces (add
handshaking, bit-blast, etc.)
Less restrictive characterization of trace
concatenation
Flesh out sequential composition of
agents based on trace concatenation
Define parallel composition for
terminating traces (fork-join, dovetailing)
Other generalizations may be needed for
future examples
Parallel composition currently defined
in terms of projection, which is not adequate for some rather low levels of abstraction
Dills distinction between failure and
success traces: helpful for characterizing
compatible compositions, interface synthesis
Worked out the relationships between the concept of conservative approximations and abstract
interpretations
Characterizing conditions under which
the inverse of an approximation
is an embedding