英语翻译II.CSP（Constrain Satisfaction Problem） We have only four

英语翻译
II.CSP（Constrain Satisfaction Problem）
We have only four variables:A,B,C and D and each of them have only two legal values,which we will write as:A1,A2 (for variable A),B1,B2 (for variable B),C1,C2 (for variable C) and D1,D2 (for variable D).The only legal assignments for each pair of variables are:
A-B:A1-B1,A2-B1
A-C:A1-C1,A2-C2
B-D:B1-D1
C-D:C2-D1
B-C:No constraint.
A-D:No constraint.
No other combination of variable values is legal.Let’s say that that”an assignment is generated” every time a variable in the problem gets a new (tentative) assignment.We assume that the variables are examined in alphabetical order and the values in numerical order.Below,we ask you to solve this problem using pure backtracking and also by using backtracking with forward checking.Stop when a valid solution is found.The search tree for this problem is given below.Each node (except the root) is labeled with the value involved in the assignment; the variable involved is obvious given the value.Your answers will be a space-separated sequence of these values involved in the assignments as they are generated during the appropriate search.For example,A1 B1 etc.:
(a) Pure backtracking:How many total assignments are made before finding an answer?
(b) Pure backtracking:Show the assignments in order.
(c) Backtracking with forward checking:How many assignments are made before finding an answer?
(d) Backtracking with forward checking:Show the assignments in order.

二.CSP(约束满意度问题).
我们只有四个变量:A、B、C、D的,而且每个人都只有两种法律价值,我们会写:A1、A2(变量),B1,B2(可变B),(C1 573℃)和D1、变量(D)输入变量.唯一合法的作业为每一对变量.
A-B:A1-B1,A2-B1
A-C:A1-C1,A2-C2
B-D:B1-D1
C-D:C2-D1
没有约束的晶体管.
A-D:没有限制.
没有其他的组合的变量值是合法的.可以这么说,“一个任务是产生“每次一个变量的问题得到一个新的(暂行)的任务.我们假设检验的变量的值按字母顺序排列的,在数字顺序.下面,我们要求你如何解决这个问题,并利用纯回溯与分析的基础上,提出了采用迭代检查.当一个有效的解决办法.对这一问题的搜索树下面给出.每个节点(除根)是用其价值的任务;参与有关的变量是显而易见的.你的答案将会是一个space-separated这些价值观的序列,因为他们参与了作业时产生的适当的搜索.例如,A1 B1等等.
(一)纯回溯多少总作业之前找到问题的答案吗?
(b):显示作业的纯回溯得井井有条.
(三)回溯分析的基础上,提出了用多少作业检查前找到问题的答案吗?
(d)和检查:指迭代的作业