@mrjbq7 Slick!  Any clue why the composition behavior is different from `with`?  The arguments are in a different order:
```factor
IN: scratchpad "a" "b" { 1 2 3 } [ nip 3array . t ] smart-with smart-with filter-index .
{ "b" "a" 0 }
{ "b" "a" 1 }
{ "b" "a" 2 }
{ 1 2 3 }
```