代码运行不了，请问问题出在哪？

Question

#输入下面的测试语句：
print(And(Proposition('P'), Proposition('Q')))
print(Not(Proposition('R')))
#我的目的是输出P/\Q，¬R，((P <-> Q) -> R)，(((P <-> Q) -> R) \/ F)等结果，但是下面的代码运行不了，也不知道哪里出错。

class Proposition:
    def __init__(self, name):
       
    def __eq__(self, other):
        if not isinstance(other, Proposition):
            return False
        return self.name == other.name

    def __str__(self):
        return self.name

    def __hash__(self):
        return hash(str(self))
  
class Not:
    def __init__(self, formula):
     


    def __eq__(self, other):
        if not isinstance(other, Not):
            return False
        return self.formula == other.formula

    def __str__(self):
        return '~' + str(self.formula)

    def __hash__(self):
        return hash(str(self))

class And:
    def __init__(self, formula_a, formula_b):
       
  
    def __eq__(self, other):
        if not isinstance(other, And):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b

    def __str__(self):
        return '(%s /\\ %s)' % (self.formula_a, self.formula_b)

    def __hash__(self):
        return hash(str(self))

class Or:
    def __init__(self, formula_a, formula_b):
       

    def __eq__(self, other):
        if not isinstance(other, Or):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b

    def __str__(self):
        return '(%s \\/ %s)' % (self.formula_a, self.formula_b)

    def __hash__(self):
        return hash(str(self))

class Implies:
    def __init__(self, formula_a, formula_b):
     

    def __eq__(self, other):
        if not isinstance(other, Implies):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b

    def __str__(self):
        return '(%s -> %s)' % (self.formula_a, self.formula_b)

    def __hash__(self):
        return hash(str(self))

class Equiv:
    def __init__(self, formula_a, formula_b):
       

    def __eq__(self, other):
        if not isinstance(other, Equiv):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b

    def __str__(self):
        return '(%s <-> %s)' % (self.formula_a, self.formula_b)

    def __hash__(self):
        return hash(str(self))

class BoolConstant:
    def __init__(self, name):
      
    def __eq__(self, other):
        if not isinstance(other, BoolConstant):
          return False
        return self.name == other.name

    def __str__(self):
        return self.name

    def __hash__(self):
        return hash(str(self))

Answer 1

这样改一下代码：

class Proposition:
    def __init__(self, name):
        self.name=name
    def __eq__(self, other):
        if not isinstance(other, Proposition):
            return False
        return self.name == other.name
    def __str__(self):
        return self.name
    def __hash__(self):
        return hash(str(self))
class Not(Proposition):
    def __init__(self, formula):
        self.formula=formula
    def __eq__(self, other):
        if not isinstance(other, Not):
            return False
        return self.formula == other.formula
    def __str__(self):
        return '~' + str(self.formula)
    def __hash__(self):
        return hash(str(self))
class And(Proposition):
    def __init__(self, formula_a, formula_b):
        self.formula_a=formula_a
        self.formula_b=formula_b
    def __eq__(self, other):
        if not isinstance(other, And):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b
    def __str__(self):
        return '(%s /\\ %s)' % (self.formula_a, self.formula_b)
    def __hash__(self):
        return hash(str(self))
class Or(Proposition):
    def __init__(self, formula_a, formula_b):
        self.formula_a=formula_a
        self.formula_b=formula_b
    def __eq__(self, other):
        if not isinstance(other, Or):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b
    def __str__(self):
        return '(%s \\/ %s)' % (self.formula_a, self.formula_b)
    def __hash__(self):
        return hash(str(self))
class Implies(Proposition):
    def __init__(self, formula_a, formula_b):
        self.formula_a = formula_a
        self.formula_b = formula_b
    def __eq__(self, other):
        if not isinstance(other, Implies):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b
    def __str__(self):
        return '(%s -> %s)' % (self.formula_a, self.formula_b)
    def __hash__(self):
        return hash(str(self))


class Equiv(Proposition):
    def __init__(self, formula_a, formula_b):
        self.formula_a = formula_a
        self.formula_b = formula_b
    def __eq__(self, other):
        if not isinstance(other, Equiv):
            return False
        return self.formula_a == other.formula_a and \
               self.formula_b == other.formula_b
    def __str__(self):
        return '(%s <-> %s)' % (self.formula_a, self.formula_b)
    def __hash__(self):
        return hash(str(self))


class BoolConstant(Proposition):
    def __init__(self, name):
        self.name=name
    def __eq__(self, other):
        if not isinstance(other, BoolConstant):
          return False
        return self.name == other.name
    def __str__(self):
        return self.name
    def __hash__(self):
        return hash(str(self))


print(And(Proposition('P'), Proposition('Q')))
print(Not(Proposition('R')))

运行结果：
F:\2021\qa\ot2>t3
(P /\ Q)
~R