🚀 go-pugleaf

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>_ dup head 2 == ?
 (2 . !*undef*)

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>_ dup (3 4) append (1 2 3 4) == ?
 (1 2)

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>'append ((swap nil ==) (swap snoc rot append cons) or) def

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$@$3$3$G!"(J

1 2     swap   ->  2 1
(1 2 3) snoc   ->  1 (2 3)
1 2 3   rot    ->  2 3 1
1 (2 3) cons   ->  (1 2 3)

$@$G$9!#(Jappend$@$N(J swap snoc rot append cons $@$NF0$-$O(J

(1 2 3) (4 5 6)
   swap ->
(4 5 6) (1 2 3)
   snoc ->
(4 5 6) 1 (2 3)
   rot  ->
1 (2 3) (4 5 6)
   append ->
1 (2 3 4 5 6)
   cons ->
(1 2 3 4 5 6)

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