
Technical details:

1. Version 1.0.0 have the following features:

	- support fairness constraints
	- support refinement for path and loop
	- support array and macro (defined by DEFINE)

	- do not support TRANS statement
	- do not support disjunctive and IWLS partitioning

2. Brief description of each file:

absAbstract.c		-	existential abstraction procedure
absAutoGenAbs.c		-	Initial abstraction generation
absRefine.c		-	automatic refinement
absVariables.c		-	formula cluster generation
absCmd.c         	-	interactive mode (not supported)
absSimulate.c		-	simulation in aSMV (for debugging)
absUtil.c		-	Misc functions related to abstraction

3. Important data structure description:

  a. Two global variables abs_expr and abs_expr_pre are used
     to store the abstraction functions. The variable
     abs_expr_pre stores the abstraction functions related
     to formula clusters which include LARGE variables. The
     remaining abstraction functions are stored in abs_expr. 
     Each abstraction function is described by a tree structure
     as follows.

	      Abstraction
	      /         \
	    /            \
        CONS             CONS
       /    \           /    \
   vars   formulas   values  CONS
			    /    \
			ADDs   relation

     The leftmost leaf "vars" denotes a list of variables included
     in the formula cluster. The leaf "formulas" denotes a list of
     atomic formulas extracted from the SMV program. The leaf
     "values" is a list of abstract values while the leaf "ADDs"
     denotes the corresponding symbolic abstract variable. The
     rightmost leaf "relation" is the abstract relation : h(x) = x'

  b. Several hash tables are used:

	depend_hash -	Given a variable, the list of variables it
			depends on are stored

	interest_hash -	if a variable is not in this hash table, it 
			will be completely abstracted

	coi_hash -	coi_hash is a subset of interest_hash. i.e.,
			if a variable is not in this hash table, it 
			will be completely abstracted. Furthermore, it
			also implies that this variable is not in the 
			influence cone of specification variables.

	abstract_hash -	stores all the abstraction functions

