def dpll(self, mode):
temp = FormulaGen(self.target_file)
temp.gen_formula()
temp.make_variables()
temp.make_clauses()
temp_formula = Formula(temp.formula_str, temp.var_lst, temp.clause_lst)
while(True):
# Real DPLL phase
# While there is a unit clause {L} in F|A, add L -> 1 to A.
temp_formula.unit_propagation()
# If F |A contains no clauses, stop & output A.
if(temp_formula.valuation() == True):
return ("SATISFIABLE", temp.var_lst)
elif(temp_formula.valuation() == False):
learned_clause = temp_formula.learning_procedure()
if len(learned_clause.clause) == 0:
return ("UNSATISFIABLE", temp.var_lst)
temp_formula.clause_lst.append(learned_clause)
temp_formula.formula_str.append(learned_clause.clause)
# Backtrack to the position where learned clause is a unit clause
temp_formula.backtrack(learned_clause)
else:
if(mode == "dlis"):
temp_formula.decision_dlis()
elif(mode == "prop"):
temp_formula.decision_proportional()
else:
temp_formula.decision_random()
