code: def p_print_list_comma(p):
      
      p[0] = p[1]
      p[0].eol = (p[3] is not None)
      p[0].appendChild(make_sentence('PRINT_COMMA'))
  
      if p[3] is not None:
          p[0].appendChild(p[3])
docs: print_list : print_list COMMA print_elem