[plt-scheme] is this a deep list ?

From: Rob Hunter (rob.hunter at gmail.com)
Date: Sun Mar 30 16:32:05 EDT 2008

Your reasoning looks good to me!


On Sun, Mar 30, 2008 at 11:59 AM, richard gere <diggerrrrr at gmail.com> wrote:
> Since this is my first posting i want to first  thank the authors of
>  htdp for such a wonderful book.
>  I also want to confirm to you that i am not a "student" in any school
>  or college.
>  >From ex 11.2.4
>  A deep-list is either
>  1. s where s is a symbol or
>  2. (cons dl empty) where dl is deep-list
>  Now from 1 we can say 'doll is a deep-list
>  >From 2 we can say (cons 'doll empty) is a deep list
>  >From 2 we can say (cons (cons 'doll empty) empty ) is a deep list
>  since it is in the form (cons dl empty)
>  Now is this a deep list , (my understanding is that it is  not
>  deep-list as per defination) :
>  (cons  (cons 'doll (cons 'robot empty)) empty)
>  why , well for it to be a deep-list the middle part has also to be a deep-list .
>  But middle part is in the form (cons 'doll dl)  i.e cons follwed by a
>  symbol followed by a deep-list and as per defination
>  there is no match , hence it is not a deep-list.
>  Please confirm if my reasoning is correct for this deep-list as per
>  defination given in the book
>  Thank you
>  veer
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