Slicing Software for Model Construction

Applying nite state veri cation techniques e g model check ing to software requires that program source code be trans lated to a nite state transition system that safely models program behavior Automatically checking such a transition system for a correctness property is typically very costly thus it is necessary to reduce the size of the transition sys tem as much as possible In fact it is often the case that much of a program s source code is irrelevant for verifying a given correctness property In this paper we apply program slicing techniques to remove automatically such irrelevant code and thus reduce the size of the corresponding transition system models We give a simple extension of the classical slicing de nition and prove its safety with respect to model checking of linear tem poral logic LTL formulae We propose various re nements to slicing that take advantage of common structural patterns appearing in LTL software speci cations Finally we discuss how this slicing strategy ts into a general methodology for deriving e ective software models using abstraction based program specialization