(self, formula, args, **kwargs)
return self.mgr.Not(self.mgr.And(lhs, self.mgr.Not(rhs)))
a -> b = !(a & !b)
a -> b = !(a & !b)
a - > b = ! ( a & !b )
def walk_implies(self, formula, args, **kwargs):
        """ a -> b = !(a & !b) """
        lhs, rhs = args
        return self.mgr.Not(self.mgr.And(lhs, self.mgr.Not(rhs)))
def walk_implies ( self , formula , args , * * kwargs ) : lhs , rhs = args return self . mgr . Not ( self . mgr . And ( lhs , self . mgr . Not ( rhs ) ) )