def propertylist_prop_names(insts, property_list):
    """
    Return the originally cased property list, based on the lexical case
    in the instances.

    If a property name is not in any instance, it is not returned.
    """
    prop_list = []
    for pname in property_list:
        for inst in insts:
            if pname in inst:
                prop_list.append(inst.properties[pname].name)
                break
    return prop_list