based on symbolic Boolean functional analyses using Or­ dered Binary Decision Diagrams (OBDDs). OBDDs have been conjectured to be an attractive representation form for Boolean functions, although cases ex­ ist for which their complexity is guaranteed to grow exponentially with input cardinality. Classes of Boolean functions which exploit the efficiencies inherent in OBDDs to a very great extent are examined in Chapter 7. Exact equa­ tions giving their OBDD sizes are derived, whereas until very recently only size bounds have been available. These size equations suggest that straight­ forward applications of OBDDs to design and test related problems may not prove as fruitful as was once thought.