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<正> Let X be set, T（X）={φ: φ ∈XXΛφ is bijective}. Two equivalence relations R and S on X are of the same type, and denoted by R～S, if （φ ∈T（X））（S = {（φ（x）, φ（y））:（x,y） ∈ R}）. Define = {S:S～E}, E（X）={:R is an equivalence relation on X}. If 0≤|X|=α, t