设 f ( x ) = ∑ i = 0 n a i x i , ( a i ∈ Z ) f(x) = \sum_{i=0}^n a_ix^i, \ (a_i\in Z) f(x)=i=0∑naixi,(ai∈Z) 如果存在素数p满足下面所有条件, (1) p ∤ a n p\nmid a_n p∤an (2) p ∣ a i , i = 0 , . . . , n − 1 p\mid a_i, i = 0,...,n-1 p∣ai,i=0,...,n−1 (2) p 2 ∤ a 0 p^2\nmid a_0 p2∤a0 那么f(x)在Q上不可约.