  We extend a semantic verification framework for hybrid systems with the
Isabelle/HOL proof assistant by an algebraic model for hybrid program stores, a
shallow expression model for hybrid programs and their correctness
specifications, and domain-specific deductive and calculational support. The
new store model yields clean separations and dynamic local views of variables,
e.g. discrete/continuous, mutable/immutable, program/logical, and enhanced ways
of manipulating them using combinators, projections and framing. This leads to
more local inference rules, procedures and tactics for reasoning with invariant
sets, certifying solutions of hybrid specifications or calculating derivatives
with increased proof automation and scalability. The new expression model
provides more user-friendly syntax, better control of name spaces and
interfaces connecting the framework with real-world modelling languages.
