Combining Model Checking and Deduction for I/O-Automata

We propose a combination of model checking and interactive theorem proving where the theorem prover is used to represent nite and in nite state systems reason about them compositionally and reduce them to small nite systems by veri ed abstractions As an example we verify a version of the Alternating Bit Protocol with unbounded lossy and duplicating channels the channels are abstracted by interactive proof and the resulting nite state system is model checked