Binary Decision Diagrams:Remarks

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Remarks

Several groups developed BDD packages, and some of them are open to the public. For example, the CUDD package [12] is well-known to BDD researchers in the U.S. Many other BDD packages may be found on the Internet. BDD packages, in general, are based on the quick search of hash tables and linked- list data structures. They greatly benefit from the property of the random access machine model [2], where any data in main memory can be accessed in constant time.

Presently, considerable research is in progress. Detection of total or partial symmetry of a logic function with respect to variables has been a very time-consuming problem, but now it can be done in a short time by BDDs [26,29]. Also, decomposition of a logic function, which used to be very difficult, can be quickly solved with BDD [5,21]. A number of new types of BDDs have been proposed in recent years. For example, the Zero-Suppressed BDD (ZBDD) [23] is useful for solving covering problems, which are used in deriving a minimal sum and other combinatorial problems. The Binary Moment Diagram (BMD) [7] is another type of BDD that is used for representing logic functions for arithmetic operations. For those who are interested in more detailed techniques related to BDDs, several good surveys [11,24,28] are available.

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