     ] if ;
 
 :: fix-right-chunk ( left right ymin ymax -- right' )
-    left last :> left-point right first :> right-point
+    left last :> left-point
+    right first :> right-point
     right-point y { [ ymin = ] [ ymax = ] } 1|| [
         right
     ] [

        dupd [ first ] dip clip-by-first
        dup empty? [ nip ] [
            [ second ] dip [ second-in-bounds? ] keep swap
            [ drop { } clone ] unless
        ] if
    ] if ;


    chunks length {
        { 0 [ chunks ] }
        { 1 [
                chunks first-point y min max between?
                chunks { } ?
            ]
        }
        [
            drop [
                chunks [ ] [ min max (make-pair) ] map-reduce
                dup first y min max between? [ , ] [ drop ] if
            ] { } make
        ]
