better comment "doc"

libs/core/looper.xtm

@@ -231,7 +231,7 @@
 (define last (lambda (num lst) (cl:last lst num)))
 ;; take first num of lst
 (define take (lambda (num lst) (cl:butnthcdr num lst)))
-;; take num at
+;; sublist: take 'num' elements starting at position 'at'
 (define sub (lambda (num at lst) (cl:butnthcdr num (cl:nthcdr at lst))))
 
 (define filter