code: def convert_to_prover9(input):
      """
      Convert a ``logic.Expression`` to Prover9 format.
      """
      if isinstance(input, list):
          result = []
          for s in input:
              try:
                  result.append(_convert_to_prover9(s.simplify()))
              except:
                  print(
                      "input %s cannot be converted to Prover9 input syntax"
                      % input
                  )
                  raise
          return result
      else:
          try:
              return _convert_to_prover9(input.simplify())
          except:
              print(
                  "input %s cannot be converted to Prover9 input syntax"
                  % input
              )
              raise
  
imports: import os
  import subprocess
  import nltk
  from nltk.inference.api import BaseProverCommand, Prover
  from nltk.sem.logic import AllExpression, AndExpression, EqualityExpression, ExistsExpression, Expression, IffExpression, ImpExpression, NegatedExpression, OrExpression
label_desc: Use image node_id 1 for calling a global function with example usage: convert_to_prover9(input) and returns: result, _convert_to_prover9