def fact(self, head):
    'ASP fact (a rule without a body).'
    symbol = (head.symbol() if hasattr(head, 'symbol') else head)
    self.out.write(('%s.\n' % str(symbol)))
    atom = self.backend.add_atom(symbol)
    self.backend.add_rule([atom], [], choice=self.cores)
    if self.cores:
        self.assumptions.append(atom)
ASP fact (a rule without a body).
def fact(self, head):
    
    symbol = (head.symbol() if hasattr(head, 'symbol') else head)
    self.out.write(('%s.\n' % str(symbol)))
    atom = self.backend.add_atom(symbol)
    self.backend.add_rule([atom], [], choice=self.cores)
    if self.cores:
        self.assumptions.append(atom)