def equal():
    """Returns a function that computes whether two temporal intervals are
    strictly equal.

    The output function expects two temporal intervals (dicts with keys 't1'
    and 't2' for the start and end times, respectively). It returns ``True`` if
    the two intervals have equal start times and equal end times.

    Returns:
        An output function that takes two temporal intervals and returns
        ``True`` if the two intervals have equal start times and equal end
        times.
    """
    return lambda intrvl1, intrvl2: intrvl1['t1'] == intrvl2['t1'] and intrvl1[
        't2'] == intrvl2['t2']
