I think this a wonderful lisp interpreter. True to the original lisp spirits.
I miss the useful copy-list function, especially since there are quite a few 'destructive' functions, for instance sort, that often must rely on previous copying of original list. I know you can write it down simply in terms of slice or select.
(define (copy-list L)
(slice L 0 (length L)))
But it would be nice to have it hard-coded.
Another first-look improvement would be to be able to type multiline expressions at the main tk window, (error 'missing parentheses' in mine). More so since there is no integrated editor. Would that be so hard ?
Thanks and congratulations.