code: def sugartex_preprocess(source: str) -> str:
      
      rep = {r'\ˎ': 'ˎ', 'ˎ': '$'}
      return re.sub(r'\\ˎ|ˎ', lambda m: rep[m.group(0)], source)
docs: Preprocess text for SugarTeX Pandoc filter.
      Replaces 'ˎ' with `$` (except `\ˎ`), replaces `\ˎ` with `ˎ`