[racket] first vs car ; last vs cdr ; empty? vs null?

Pardon me, but going back a bit where the blog about switching to immutable
lists was mentioned...I saw an interesting comment about immutability and
eq?.  Have any mathematicians come up with an answer for the meaning of eq?
on permanently distinct but equivalent and immutable objects, e.g. (eq?
(cons 3 2) (cons 3 2))?  What about on immutable objects that have mutable
internal state, e.g. memoizing functions?  Naive-but-memoized (fib 1000) is
not necessarily the same as (fib 1000), unless the answer doesn't depend on
the number of universes that have bigbanged meanwhile.



On Fri, Mar 7, 2014 at 2:31 PM, Daniel Carrera <dcarrera at gmail.com> wrote:

> Thanks.
>
>
> On 7 March 2014 20:22, Harry Spier <vasishtha.spier at gmail.com> wrote:
>
>> See also this previous thread on the Racket list.
>>  http://www.mail-archive.com/users%40racket-lang.org/msg12161.html
>>
>>
>>
>>
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