slightly changed the truth table function
forgot something
fixed the truth table problem, changed test towards recognizable output
added a test case for Formula parsers
added the two constant Formulas for internal use
added function to reduce constants in a Formula, let the function that provides the Formula of an OBDD call it
the parent list of an OBDD node is now initialized
fixed minor mistake in reduceConstants
added test case for retrieving an OBDDs Formula
added a computed table to the apply method
added the negation algorithm on OBDDs, added some CT usages to OBDD methods, fixed some CT mistakes
added satisfaction algorithm, fixed the computed tables again, possibly semaphores needed
a few comment changes