Python:实现DPLL(davisb putnamb logemannb loveland)算法
from __future__ import annotations
import random
from collections.abc import Iterable
class Clause:
"""
A clause represented in Conjunctive Normal Form.
A clause is a set of literals, either complemented or otherwise.
For example:
{A1, A2, A3'} is the clause (A1 v A2 v A3')
{A5', A2', A1} is the claus