ΧChek: A Multi-valued Model-Checker

Model-Checking Software Using Precise Abstractions

“…For the model-checking phase, our current implementation uses a modification of our existing model-checker χ Chek [CDG02] which can naturally analyze models expressed in Belnap and Kleene logic. Just as other implementations of the CEGAR framework, we extended χ Chek's algorithms to exploit the control-flow graph of the program.…”

Why Waste a Perfectly Good Abstraction?

“…The latter step involves multivalued model-checking, e.g., using the algorithm implemented in χ Chek [5]. In Section 4.1, we describe how to perform model-checking with Belnap logic using standard BDD packages.In Section 4.2, we show how to find additional predicates to refine the abstraction if the result of model-checking a formula ϕ is inconclusive.…”

Data structures for symbolic multi-valued model-checking

“…In this section we study the effects of the different representations of mv-sets on some realistic problems using our multi-valued model-checker © Chek [22]. The problems come with a series of CTL questions, thus providing us with a workload and letting us explore the relationship between the size of decision diagrams, discussed in detail in the previous section, and the running times of the verification.…”

“…In our previous work, we made several attempts to implement a symbolic multi-valued model-checker [23,19,21,22]. The first presentation, [23], represented each mv-set by associating each value of the algebra with a corresponding classical set, using explicit tables to compute mv-set operations and their inverses (see discussion in the beginning of Section 7).…”