def is_control(line, index, word):
  """ Return whether LINE[INDEX] is actual the start position of
  control statement WORD.  It must be followed by an opening
  parantheses and only whitespace in between WORD and the '('.
  """
  if index > 0:
    if not (line[index-1] in [' ', '\t', ';']):
      return False

  index = index + len(word)
  parantheses_index = line.find('(', index)
  if parantheses_index == -1:
    return False

  while index < parantheses_index:
    if not (line[index] in [' ', '\t',]):
      return False

    index += 1

  return True