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From: STCS8004%IRUCCVAX.UCC.IE@mitvma.mit.EDU
Newsgroups: comp.lang.scheme
Subject: Keywords do not apply
Message-ID: <9105021642.aa12771@mc.lcs.mit.edu>
Date: 2 May 91 16:58:00 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 33

In reply to:

>  "Alan@lcs.mit.EDU"  "Alan Bawden"  2-MAY-1991 02:00:47.52
>   ...

> If you use eta-conversion to argue that

>  (LAMBDA (X Y) (AND X Y))

> should be equivalent to just

>  AND

> then nothing stops me from using eta-conversion to argue that

>  (LAMBDA (X Y) (LAMBDA X Y))

> should be equivalent to just

>  LAMBDA

Oh, yes there is!  Eta-conversion is valid ONLY for FUNCTIONS!  Thus
whilst (in lambda calculus) it is valid to have

    (lambda (x) (sqrt x)) =  sqrt

it is NOT valid to claim

    (lambda (x) (3 x))  = 3.

If  you want  to argue  that AND  is not  a function,  then I  disagree.

G. Oulsnam                                 stcs8004@iruccvax.ucc.hea.ie