There are two groups of researchers who are interested in designing network protocols and who cannot (yet) effectively communicate with one another c- cerning these protocols. The first is the group of protocol verifiers, and the second is the group of protocol implementors. The main reason for the lack of effective communication between these two groups is that these groups use languages with quite different semantics to specify network protocols. On one hand, the protocol verifiers use specification languages whose semantics are abstract, coarse-grained, and with large atom- ity. Clearly,...