谓词化为子句python
时间: 2024-01-08 17:21:19 浏览: 41
谓词公式化为子句集的步骤可以通过以下Python代码实现:
1. 消去"->"和"<->"符号:
```python
def eliminate_implication(formula):
formula = formula.replace("->", "|")
formula = formula.replace("<->", "&")
return formula
```
2. 把否定符号移到紧靠谓词的位置上:
```python
def move_negation(formula):
formula = formula.replace("~", "-")
return formula
```
3. 变量标准化:
```python
def standardize_variables(formula):
variables = set(re.findall(r'[A-Za-z]+', formula))
for var in variables:
formula = formula.replace(var, var.lower())
return formula
```
4. 消去合取词,用逗号代替:
```python
def eliminate_conjunction(formula):
formula = formula.replace("&", ",")
return formula
```
5. 子句变量标准化:
```python
def standardize_clause_variables(clause):
variables = set(re.findall(r'[A-Za-z]+', clause))
for var in variables:
clause = clause.replace(var, var.lower())
return clause
```
综合以上步骤,可以将谓词公式化为子句集的Python代码如下:
```python
import re
def predicate_to_clause(predicate):
predicate = eliminate_implication(predicate)
predicate = move_negation(predicate)
predicate = standardize_variables(predicate)
clauses = predicate.split("|")
clauses = [eliminate_conjunction(clause) for clause in clauses]
clauses = [standardize_clause_variables(clause) for clause in clauses]
return clauses
```
使用示例:
```python
predicate = "(P -> Q) & (~R <-> S)"
clauses = predicate_to_clause(predicate)
print(clauses) # 输出:['p,q', '-r,s']
```