(self, formula)
return not self.is_sat(formula)
Checks unsatisfiability of the formula w.r.t. the current state of
        the solver.

        Previous assertions are taken into account. See :py:func:`is_sat`

        :type formula: FNode
        :returns: Whether formula is unsatisfiable
        :rtype: bool
Checks unsatisfiability of the formula w.r.t. the current state of
        the solver.
Checks unsatisfiability of the formula w . r . t . the current state of the solver .
def is_unsat(self, formula):
        """Checks unsatisfiability of the formula w.r.t. the current state of
        the solver.

        Previous assertions are taken into account. See :py:func:`is_sat`

        :type formula: FNode
        :returns: Whether formula is unsatisfiable
        :rtype: bool
        """
        return not self.is_sat(formula)
def is_unsat ( self , formula ) : return not self . is_sat ( formula )