ddr@margaux.inria.fr (Daniel de Rauglaudre) (02/22/91)
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
kjell@saturn.ucsc.edu (Kjell Post) (02/24/91)
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
brian@comp.vuw.ac.nz (Brian Boutel) (02/25/91)
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
wg@opal.cs.tu-berlin.de (Wolfgang Grieskamp) (02/25/91)
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
hensm@csc2.essex.ac.uk (Henson M C) (02/27/91)
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.