def get_relational(directory: str) -> set:
    """
    Return tests from the /spacer-benchmarks/relational
    that don't return 'unknown' and don't work long.
    """

    files = {
        'point-location-nr.52.smt2',
        'point-location-nr.53.smt2',
        'point-location-nr.50.smt2',
        'inc-loop-1.smt2',
        'point-location-nr.54.smt2',
        'mccarthy-monotone.smt2',
        'mccarthy-equivalent.smt2',
        'point-location-nr.51.smt2',
        'point-location-nr.49.smt2',
        'inc-loop-2.smt2',
        'inc-loop-5.smt2'
    }
    seeds = {directory +
             'spacer-benchmarks/relational/' +
             file for file in files}
    return seeds