(self)
return not self.variables and not self.metas
True if the domain has no variables of any kind
True if the domain has no variables of any kind
True if the domain has no variables of any kind
def empty(self):
        """True if the domain has no variables of any kind"""
        return not self.variables and not self.metas
def empty ( self ) : return not self . variables and not self . metas