code: def _read_valuation_line(s):
      """
      Read a line in a valuation file.
  
      Lines are expected to be of the form::
  
        noosa => n
        girl => {g1, g2}
        chase => {(b1, g1), (b2, g1), (g1, d1), (g2, d2)}
  
      :param s: input line
      :type s: str
      :return: a pair (symbol, value)
      :rtype: tuple
      """
      pieces = _VAL_SPLIT_RE.split(s)
      symbol = pieces[0]
      value = pieces[1]
      # check whether the value is meant to be a set
      if value.startswith("{"):
          value = value[1:-1]
          tuple_strings = _TUPLES_RE.findall(value)
          # are the set elements tuples?
          if tuple_strings:
              set_elements = []
              for ts in tuple_strings:
                  ts = ts[1:-1]
                  element = tuple(_ELEMENT_SPLIT_RE.split(ts))
                  set_elements.append(element)
          else:
              set_elements = _ELEMENT_SPLIT_RE.split(value)
          value = set(set_elements)
      return symbol, value
  
imports: import inspect
  import re
  import sys
  import textwrap
  from pprint import pformat
  from nltk.decorators import decorator
  from nltk.sem.logic import AbstractVariableExpression, AllExpression, AndExpression, ApplicationExpression, EqualityExpression, ExistsExpression, Expression, IffExpression, ImpExpression, IndividualVariableExpression, IotaExpression, LambdaExpression, NegatedExpression, OrExpression, Variable, is_indvar
label_desc: Use image node_id 5 for calling a global function with example usage: _read_valuation_line(s) and returns: symbol,  value