# [plt-scheme] The Lambda Calculus behind functional programming

On Sun, Sep 02, 2007 at 12:05:58AM +0200, Jos Koot wrote:
>*
*>*
*>* ((((lambda(x)((((((x x)x)x)x)x)x))
*>* (lambda(x)(lambda(y)(x(x y)))))
*>* (lambda(x)(write x)x))
*>* 'greeting)
*>* ----- Original Message -----
*>* From: <hendrik at topoi.pooq.com>
*>* To: <plt-scheme at list.cs.brown.edu>
*>* Sent: Saturday, September 01, 2007 10:14 PM
*>* Subject: Re: [plt-scheme] The Lambda Calculus behind functional programming
*>*
*>*
*>* >On Sat, Sep 01, 2007 at 02:53:58PM +0200, Jos Koot wrote:
*>* >>----- Original Message -----
*>* >>From: "Jens Axel Søgaard" <jensaxel at soegaard.net>
*>* >>To: "Jos Koot" <jos.koot at telefonica.net>
*>* >>Cc: "PLT Scheme" <plt-scheme at list.cs.brown.edu>
*>* >>Sent: Friday, August 31, 2007 8:38 PM
*>* >>Subject: Re: [plt-scheme] The Lambda Calculus behind functional
*>* >>programming
*>* >>
*>* >>
*>* >>>Jos Koot wrote:
*>* >>>>Would it make sense to present a formal mathematical definition of a
*>* >>real
*>* >>>>number on primary school as a starting point for elementary arithmetics?
*>* >
*>* >formal??? probably not. Informal? maybe. The essence that has to be
*>* >conveyed is
*>* > You've got a real number when you can approximate it as precisely as
*>* >you want.
*>*
*>*
*>* Given an arbitrary real number you can approximate it
*>* as precisely as you want by means of fractions
*>* (unless "as precisely as you want" includes approximation-approximated=0)
*
That's exactly what I mean. The essence or real numbers is their
approximability by rationals.
>* Therefore I do not understand what you mean.
*
I think you do. You just said it yourself. You just didn't think I
could be meaning that.
>*
*>* Jos Koot
*>*
*
-- hendrik