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+; P18 Extract a slice from a list.
+; Given two indices, I and K, the slice is the list containing the elements between the 
+; I'th and K'th element of the original list (both limits included). Start counting the elements with 1.
+
+(def a (list "a" "b" "c" "d" "e" "f" "g" "h" "i" "k"))
+
+(func my-slice (lst idx1 idx2)
+    (my-slice lst idx1 idx2 (list)))
+
+(func my-slice (lst :nil idx1 idx2 acc) acc)
+
+(func my-slice (lst :{:any} idx1 idx2 acc)
+    (my-slice 
+        (rest lst) 
+        (-- idx1) 
+        (-- idx2) 
+        (if
+            (or
+                (> idx1 1)
+                (< idx2 1))
+            acc
+            (append acc (first lst)))))
+
+(func -- (num) (- num 1))
+
+(print (->string a))
+(print (->string (my-slice a 3 7)))