First-order logic
inference rules for quantifiers {9.1.1}
For the existential quantifier,
If the knowledge base there, the presence of V, α, is then such, v can be substitution to be k. k is there have been no constants.
If there are front quantifiers have universal quantifier, it can not replace:
If there quantifier is bound by the universal quantifier, to instantiate this quantifier, how do? x and y must have a function, x depends on y, so the instantiation when x, x becomes a function of y.
m (y) is skolem function, where there have been no other function.
If there is any universal quantifier plurality of front quantifier, then substituting into the xk f (x1, ... xk-1 ) as a function
Universal quantifier and existential quantifier can substitute many times?
If x exists, there may be a representative of there may be two, if substitution quantifier, representing the presence of at least twice.
So for the existential quantifier, only one substitution
Unity, CNF, comes down
If x and y are
The so-called unity: find two statements-one yuan process.
Suppose UNIFY input
requirements of unity element α and β.
If the two statements entered their unity yuan may not be the only
normal looking-one yuan, to find the most simple unity yuan, called MGU.
Two statements of variables to do a standardized, one of the variables to change a name, such as, change the x x1,
example:
Erasing the first step contains,
a second portion, the front of the universal quantifier non moved inside, interconversion between universal quantifier, and existential quantifier,
A third step, conversion of the same name, variable name. These two different y is y, y change the name in which a
fourth step of considering skolemize, z is the presence of any x within the jurisdiction, and then transform it into a function of x.
After here to get this statement, the current form is not
把这个CNF变成三个子句 ：
一旦把一阶逻辑变成子句集合，
在命题逻辑里面归结时， 对于两条给定子句， 寻找他们的互补文字， 消去互补文字， 剩余部分进行析取。
给定KB， 的情况下导出矛盾。 这样的情况对应到一阶逻辑里面。
在一阶逻辑中， 归结过程如下。
通过li , 和mj 的代换， 得到互补文字。
例子：
1、 B 和非B 互补 ， 进行归结， 得（3）
2、
3、
1、问题转换成逻辑语句
2、 逻辑于娟转化为CNF
3、把非阿尔法转化为CNF
4、归结推理导出新的语句， 直到产生矛盾， 归结出空语句。
5、
前面黑色的是知识库， 后面红色的是要证明的结论。
1、 转化为CNF
2、 这里面的两个x 和y 是不同的x 和y , 在必要时需要标准化。
结论的
3、 二三归结， y 代换成a ,
例子2 ， 证明它是不可满足的， 要归结出空子句。
首先转化为CNF ，
例子3：
1、2 语句归结， 如果把y 代换成x , 第二句中的y , 代换成x .
Example 4:
every patient like every doctor, no one likes to quack.
1, translated into logical statement, find the premise and conclusion in front of so is the premise behind the conclusions.
Y and contains supporting any arbitrary y if y is a doctor, then x like doctors.
And contains supporting universal quantifier, matching the conjunction and existential quantifiers.
There are some simple strategies can help us improve attributed sales unit first, single-word statement attributed priority
Each defining words can be converted into a positive character