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part b.  Write the sublist procedure.  It can utilize your 
         list-head and the Scheme list-tail procedures for implementation.
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> (define myList '(1 2 3 4 5 6 7 8 9 10 11 12))
> (sublist myList 2 10)
(2 3 4 5 6 7 8 9 10)
> (sublist myList 5 (length myList))
(5 6 7 8 9 10 11 12)
> (sublist myList 5 9)
(5 6 7 8 9)
> (sublist myList 1 4)
(1 2 3 4)