def scan4(alines):
    """mark explicitly paragraphical list items"""
    explicitly_paragraphical = True
    for aline in alines:
        if aline.type == 'empty':
            explicitly_paragraphical = True
        else:
            if aline.type in ['ordered', 'unordered']:
                aline.explicitly_paragraphical = explicitly_paragraphical
            explicitly_paragraphical = False
    return alines
