def dot_to_dict(values):
    """Convert dot notation to a dict. For example: ["token.pos", "token._.xyz"]
    become {"token": {"pos": True, "_": {"xyz": True }}}.

    values (iterable): The values to convert.
    RETURNS (dict): The converted values.
    """
    result = {}
    for value in values:
        path = result
        parts = value.lower().split(".")
        for i, item in enumerate(parts):
            is_last = i == len(parts) - 1
            path = path.setdefault(item, True if is_last else {})
    return result