  Continuous invariants are an important component in deductive verification of
hybrid and continuous systems. Just like discrete invariants are used to reason
about correctness in discrete systems without having to unroll their loops,
continuous invariants are used to reason about differential equations without
having to solve them. Automatic generation of continuous invariants remains one
of the biggest practical challenges to the automation of formal proofs of
safety for hybrid systems. There are at present many disparate methods
available for generating continuous invariants; however, this wealth of diverse
techniques presents a number of challenges, with different methods having
different strengths and weaknesses. To address some of these challenges, we
develop Pegasus: an automatic continuous invariant generator which allows for
combinations of various methods, and integrate it with the KeYmaera X theorem
prover for hybrid systems. We describe some of the architectural aspects of
this integration, comment on its methods and challenges, and present an
experimental evaluation on a suite of benchmarks.
