Focus points and convergent process operators (A proof strategy for protocol verification)  
authors  Groote, J.F.; Springintveld, J. 
source  Logic Group Preprint Series, volume: 142 (2008) 
full text  [Full text] 
document type  Preprint 
discipline 

abstract  We present a strategy for finding algebraic correctness proofs for communication systems.
It is described in the setting of μCRL [11], which is, roughly, ACP [2,3] extended with a
formal treatment of the interaction between data and processes.
The strategy has already been applied successfully in [4] and [10], but was not explicitly
identified as such. Moreover, the protocols that were verified in these papers were rather
complex, so that the general picture was obscured by the amount of details. In this paper, the proof strategy is materialised in the form of definitions and theorems. These results
reduce a large part of protocol verification to a number of trivial facts concerning data
parameters occurring in implementation and specification. This greatly simplifies protocol
verifications and makes our approach amenable to mechanical assistance; experiments in
this direction seem promising.
The strategy is illustrated by several small examples and one larger example, the
Concurrent Alternating Bit Protocol
(CABP). Although simple, this protocol contains a
large amount of internal parallelism. so that all relevant issues make their appearance. 