Reduction of OBDDs in linear time

Ordered binary decision diagrams (OBDDs) play an important role as data structure for Boolean functions. They are used, e.g., in the logical synthesis process, for verification and test pattern generation, and as part of CAD tools. For a given ordering of the variables and a given Boolean function f the reduced OBDD, i.e. the OBDD of minimal size, is unique (up to isomorphisms) and can be computed from any OBDD G for f of size | G| in time O(¦ G¦log¦ G¦). A new reduction algorithm which works in optimal linear time O(| G|) is presented.