(@ average list @fp +-
    (0 .weight .divider .total ..)
    (.* list item >
        (+= 1 .weight)
        (+= (* weight (# fp item)) .total)
        (+= weight .divider)
    )
    ([divider] >
        ((/ divider) total)
    >
        0
    )
+
    {A|L} list
)

