code: def to_cnf(first, second):
      """
      Convert this split disjunction to conjunctive normal form (CNF)
      """
      if isinstance(first, AndExpression):
          r_first = to_cnf(first.first, second)
          r_second = to_cnf(first.second, second)
          return r_first & r_second
      elif isinstance(second, AndExpression):
          r_first = to_cnf(first, second.first)
          r_second = to_cnf(first, second.second)
          return r_first & r_second
      else:
          return first | second
  
label_desc: Use image node_id 2 for calling a global function with example usage: to_cnf(first, second) and returns: unknown, unknown, unknown