Formal verification using edge-valued binary decision diagrams

We present a new data structure called edge-valued binary-decision diagrams (EVBDD). An EVBDD is a directed acyclic graph, that provides a canonical and compact representation of functions that involve both Boolean and integer quantities. In general, EVBDDs provide a more versatile and powerful representation than ordinary binary decision diagrams. We first describe the structure and properties of EVBDDs, and present a general algorithm for performing a variety of binary operations. Next, we describe an important extension of EVBDDs, called Structural EVBDDs, and show how they can be used for hierarchical verification.