[
    all-slots [ name>> ] map
    [
        reverse! members 
        [ length ] keep 
    ] keep
] keep

[
        [ narray reverse! ] dip
        [ swap 2array ] 2map
] 2dip

[
    initial-values reverse!
    [ 2array ] 2map
    swap assoc-union!
    reverse! [ last ] each
] 
[
    boa
] bi