def check_sequence(predecessor_list, sequence):
    """ Checks if predecessors are in the sequence"""
    check = False
    if predecessor_list == set():
        check = None
        return check

    pred_set = set()
    seq_set = set()
    for pred in predecessor_list:
        pred_set.add(pred.name)
    for elem in sequence:
        seq_set.add(elem[2].name)

    if pred_set.issubset(seq_set):
        check = True
        return check

    return check