现有一个由N个布尔值组成的序列A，给出一些限制关系，比如A[x] AND A[y]=0、A[x] OR A[y] OR A[z]=1等，要确定A[0..N-1]的值，使得其满足所有限制关系。这个称为SAT问题，特别的，若每种限制关系中最多只对两个元素进行限制，称为2-SAT问题-Present a Boolean value of N consisting of the sequence A, the relationship given some restrictions, such as A [x] AND A [y] = 0, A [x] OR A [y] OR A [z] = 1, etc. To determine the A [0 .. N-1] value, making its relationship to meet all of restriction. This is called SAT problem, particularly if the relationship of each restriction on the maximum limit of two elements, known as 2-SAT problem