def format_serialized(serialized):
    """Formats the serialized logical form to reduce the number of tokens.

    The intent and slot labels are lower-cased and broken into words.
    Example: "[IN:SET_ALARM" --> "[IN set alarm ="

    The close brackets are also merged with the preceding token to avoid an extra
    space token after tokenization.

    Args:
      serialized: Serialized logical form string

    Returns:
      formatted logical form string.
    """
    lf_toks = []
    for tok in serialized.split():
        if tok == "]":
            lf_toks.append(tok)
        elif tok[0] == "[":
            prefix, suffix = tok[1:].split(":")
            lf_toks.append(" [" + prefix)
            lf_toks.append(" " + suffix.lower().replace("_", " "))
            lf_toks.append(" =")
        else:
            lf_toks.append(" " + tok)
    return "".join(lf_toks).strip()