满足连续性、零次齐次及瓦尔拉斯定理的超额需求函数必存在一个不动点，即存在均衡（见[12,13]）。
Homogeneous of degree zero in all prices , Walras ' Law together with continuity gurantee that excess demand functions must have a zero . or in more familiar terminology , that equilibrium prices must exist ( see [ 12,13 ] ) .
瓦尔拉斯需求函数