def _model_oper(oper, **kwargs):
 return (lambda left, right: _CompoundModelMeta._from_operator(oper, left, right, **kwargs))

def _model_oper ( oper , ** kwargs ) : return ( lambda left , right : _CompoundModelMeta . _from_operator ( oper , left , right , ** kwargs ) )
returns a function that evaluates a given python arithmetic operator between two models .