🚀 go-pugleaf

In article <1952@seti.inria.fr> ddr@margaux.inria.fr (Daniel de Rauglaudre) writes:
>There is a question of great importance in our institute: why "lambda"
>in "lambda calculus" ? Why not "alpha" or "dzeta" or any other symbol ?
>Does anybody know the origin of this choice ? Thank you for you answers.
>
>	Daniel de Rauglaudre
>	INRIA - France
>	ddr@inria.inria.fr


You could ask Church (I think he's still alive) but I don't think that
will help you because the last time they asked him he didn't remember
why he picked lambda. 

There are some speculations on lambda being a degenerate form of the
caret-sign (``^'') but I recall Church saying that "it's possible but
I don't know...".  

--Kjell
--
      For athletes and programmers,  ! Kjell E. Post
a woman is the end of their career.  ! CIS/CE
                                     ! University of California, Santa Cruz
              -- A.Wickberg          ! Email: kjell@saturn.ucsc.edu

In article <12733@darkstar.ucsc.edu>, kjell@saturn.ucsc.edu (Kjell Post)
writes:
|> In article <1952@seti.inria.fr> ddr@margaux.inria.fr (Daniel de
|> Rauglaudre) writes:
|> >There is a question of great importance in our institute: why
|> "lambda"
|> >in "lambda calculus" ? Why not "alpha" or "dzeta" or any other
|> symbol ?
|> >Does anybody know the origin of this choice ? Thank you for you
|> answers.
|> >
|> >	Daniel de Rauglaudre
|> >	INRIA - France
|> >	ddr@inria.inria.fr
|> 
|> 
|> You could ask Church (I think he's still alive) but I don't think
|> that
|> will help you because the last time they asked him he didn't
|> remember
|> why he picked lambda. 
|> 
|> There are some speculations on lambda being a degenerate form of the
|> caret-sign (``^'') but I recall Church saying that "it's possible
|> but
|> I don't know...".  

I read somewhere (and I would like to be reminded where) that the origin
is connected with the carat-sign.

In, I think, Whitehead and Russell's Principia Mathematica, the carat is
used to mark each occurance of a bound variable in an expression. Later,
the usage got changed to mark each bound variable once only, by
prefixing the expression with a big caret and the name of the bound
variable.  The big caret is like a capital lambda /\. Later still, (for
printer's convenience?) the lambda became lower case.

--brian

-- 
Internet: brian@comp.vuw.ac.nz
Postal: Brian Boutel, Computer Science Dept, Victoria University of Wellington,
        PO Box 600, Wellington, New Zealand
Phone: +64 4 721000

ddr@margaux.inria.fr (Daniel de Rauglaudre) writes:

>There is a question of great importance in our institute: why "lambda"
>in "lambda calculus" ? Why not "alpha" or "dzeta" or any other symbol ?
>Does anybody know the origin of this choice ? Thank you for you answers.

This seems to be quite easy: lambda just sounds so nice. At least, better 
then alpha. Out of concurrence: "dzeta". Just try to think of "omega" -
terrible, and, BTW, preloaded.

Hey, you wont like to make a phonetic, psychologic, historic, what you like,
dissertation on this subject? It might be really appreciated. 

Yes, the lambda calculus induces so really deep perception again and 
again. 

--
Wolfgang Grieskamp 
wg@opal.cs.tu-berlin.de tub!tubopal!wg wg%opal@DB0TUI11.BITNET

The following I have 'known' for years and years - but I can't remember
who on earth told me. Moreover I have not even checked the reference.
I can't be the only person in the world who believes what follows - if
it's false that will be as interesting to me as it's 'truth' currently is !!!!

.......

In Russell & Whitehead's 'principia' variables which occur in expressions
have a circumflex ^ over them when they appear bound. It seems that at some
point the notation mutated so that the bound variables were introduced with
a larger circumflex - which of course looks like a capital lambda - later a
lower case lambda was used by Church when he developed his calculus.