(thirds '(a b c d e f g))
should return: (a d g)
;
(thirds '((a b) c (d e f) g (h i)))
should return ((a b) g))
(thirds '())
should return the empty list;
The second function is SWAP
The third function is EVENATOM
(thirds '(a b c d e f g))
should return: (a d g)
;
(thirds '((a b) c (d e f) g (h i)))
should return ((a b) g))
(thirds '())
should return the empty list;
The second function is SWAP
The third function is EVENATOM
It seems that all this functions were part of someone else's assignment, if you take the time to search for them there are several answers. Disclaimer: I'll link my own solutions, but there are others there, just as good.