Parameters
    ----------
    real_seg : list of integers
        The segmentation as it should be.
    pred_seg : list of integers
        The predicted segmentation.

    Returns
    -------
    bool :
        True, if strokes of two different symbols are put in the same symbol.

def has_missing_break(real_seg, pred_seg):
    """
    Parameters
    ----------
    real_seg : list of integers
        The segmentation as it should be.
    pred_seg : list of integers
        The predicted segmentation.

    Returns
    -------
    bool :
        True, if strokes of two different symbols are put in the same symbol.
    """
    for symbol_pred in pred_seg:
        for symbol_real in real_seg:
            if symbol_pred[0] in symbol_real:
                for stroke in symbol_pred:
                    if stroke not in symbol_real:
                        return True
    return False