def standardize_variables(sentence, dic=None):
    """Replace all the variables in sentence with new variables.
    >>> e = expr('F(a, b, c) & G(c, A, 23)')
    >>> len(variables(standardize_variables(e)))
    3
    >>> variables(e).intersection(variables(standardize_variables(e)))
    set([])
    >>> is_variable(standardize_variables(expr('x')))
    True
    """
    if dic is None: dic = {}
    if not isinstance(sentence, Expr):
        return sentence
    elif is_var_symbol(sentence.op):
        if sentence in dic:
            return dic[sentence]
        else:
            v = Expr('v_%d' % standardize_variables.counter.next())
            dic[sentence] = v
            return v
    else:
        return Expr(sentence.op,
                    *[standardize_variables(a, dic) for a in sentence.args])
def standardize_variables(sentence, dic=None):
    """Replace all the variables in sentence with new variables.
    >>> e = expr('F(a, b, c) & G(c, A, 23)')
    >>> len(variables(standardize_variables(e)))
    3
    >>> variables(e).intersection(variables(standardize_variables(e)))
    set([])
    >>> is_variable(standardize_variables(expr('x')))
    True
    """
    if dic is None: dic = {}
    if not isinstance(sentence, Expr):
        return sentence
    elif is_var_symbol(sentence.op):
        if sentence in dic:
            return dic[sentence]
        else:
            v = Expr('v_%d' % standardize_variables.counter.next())
            dic[sentence] = v
            return v
    else:
        return Expr(sentence.op,
                    *[standardize_variables(a, dic) for a in sentence.args])
def standardize_variables ( sentence , dic = None ) : if dic is None : dic = { } if not isinstance ( sentence , Expr ) : return sentence elif is_var_symbol ( sentence . op ) : if sentence in dic : return dic [ sentence ] else : v = Expr ( 'v_%d' % standardize_variables . counter . next ( ) ) dic [ sentence ] = v return v else : return Expr ( sentence . op , * [ standardize_variables ( a , dic ) for a in sentence . args ] )
Replace all the variables in sentence with new variables.
    >>> e = expr('F(a, b, c) & G(c, A, 23)')
    >>> len(variables(standardize_variables(e)))
    3
    >>> variables(e).intersection(variables(standardize_variables(e)))
    set([])
    >>> is_variable(standardize_variables(expr('x')))
    True
Replace all the variables in sentence with new variables . >>> e = expr ( F ( a b c ) & G ( c A 23 ) ) >>> len ( variables ( standardize_variables ( e ))) 3 >>> variables ( e ) . intersection ( variables ( standardize_variables ( e ))) set ( [] ) >>> is_variable ( standardize_variables ( expr ( x ))) True