def is_float4x4(items):
    """Verify that the sequence contains 4 sequences of each 4 :obj:`float`.

    Parameters
    ----------
    items : iterable
        The sequence of items.

    Returns
    -------
    bool
    """
    return (
        len(items) == 4 and
        all(
            len(item) == 4 and
            all(isinstance(i, float) for i in item) for item in items
        )
    )