code: def stem(word):
      if len(word) <= 2:
          return word
      word = remove_initial_apostrophe(word)
  
      # handle some exceptional forms
      if word in exceptional_forms:
          return exceptional_forms[word]
  
      word = capitalize_consonant_ys(word)
      r1 = get_r1(word)
      r2 = get_r2(word)
      word = step_0(word)
      word = step_1a(word)
  
      # handle some more exceptional forms
      if word in exceptional_early_exit_post_1a:
          return word
  
      word = step_1b(word, r1)
      word = step_1c(word)
      word = step_2(word, r1)
      word = step_3(word, r1, r2)
      word = step_4(word, r2)
      word = step_5(word, r1, r2)
      word = normalize_ys(word)
  
      return word
  
imports: import re
label_desc: Use image node_id 20 for calling a global function with example usage: stem(word) and returns: word, word, exceptional_forms, word