A Lambda Logo Tour
(and why LISP languages using λ as logo should not be looked upon
kindly)
Xah Lee, 2002-02
Dear lispers,
The lambda character λ, always struck a awe in me, as with other
mathematical symbols. In my mind, i imagine that those obscure math
symbolism are etched in stone by god. A salient example is the book
cover Concrete Mathematics by Ronald Graham et al. (See it here:
http://xahlee.org/UnixResource_dir/bcb/concrete-math.jpg.) Here we see
the summation sign ∑ etched in stone. The summation sign happens to
be my favorite math symbol. (chosen as my website signet:
http://xahlee.org/Icons_dir/icon_sum.gif XahLee.org signet)
These symbols are not to be trifled with. If anyone puffs in as much
half a snicker, i wish god strikes a thunder upon their impudence.
The Greek lambda symbol is used in a branch of logic called lambda
calculus. The theories of lambda calculus is what functional languages
are based on, thus many functional languages's logo feature the lambda.
Here is a sampling:
MIT Scheme logo
MIT Scheme's logo features a recursive shield with lambda
http://www.swiss.ai.mit.edu/projects/scheme/
Schemer.org's logo
Schemer.org's logo has a modernized look. It is a simple lambda inside
a O figuration. http://www.schemers.org/ (the O figure is supposed to
be a pair of parenthesis)
PLT Scheme logo
PLT Scheme logo, notable is the red/white/blue coloring scheme.
http://www.plt-scheme.org/
MzScheme
MzScheme logo features a lambda besides a Chinese character 文 (wen2).
The character means written language.
http://www.cs.rice.edu/CS/PLT/packages/mzscheme/
Common Lisp HTTP server logo
the Common Lisp HTTP server logo.
http://www.ai.mit.edu/projects/iiip/doc/cl-http/home-page.html
Scheme Shell logo
Scheme shell scsh logo is a lamba inside a bivalve, perhaps most
artistic of the bunch: http://www.scsh.net/
Haskell logo
Haskell language logo is a plain lambda: http://haskell.org/
Hugs98 logo
The Haskell interpreter Hugs98 features a 3D lambda with projected
shadow http://www.haskell.org/hugs/
Yale Haskell logo Yale Haskell bullfrog
Yale Haskell project used a logo that features symbols in lambda
calculus including the lambda, and also a bullfrog head. Quite funny
and beautiful. (the bullfrog logo origin is explained at the bottom.
i.e. that of parody to Yale's bulldog logo)
http://web.archive.org/web/20000301023909/http://www.cs.yale.edu/haskell/yale-fp.html
The book cover Structure & Interpretation of Computer Programs by
Abelson & Sussman, features a wizard and witch talking with prominent
lambda, and a monster foot of the table showing: see:
http://xahlee.org/UnixResource_dir/sicp-cover.jpg
I love these lambda-featuring logos. However, i have a complaint. As
most of you know, lisp languages are not purely functional languages.
Subroutines in lisps easily have side-effects, and sometimes
non-functional programing methodologies such as OOP are actually
encouraged in lisp. As most of you know, the lambda symbol chosen by
functional languages is to signify no side-effects. In this respect, i
find the lisp languages not totally deserving the use of lambda in
their logo. As i have expressed before, mathematical symbols are not to
be trifled with, and the Schemers have tainted my mathematics, strickly
speaking.
Although i have these minor objections with lispers using the lambda
symbol, but overall i think the lispers and i share a more important
common goal. That is, to kill all imperative programing ignoramuses of
the world. Once the unix and c and perl and otherwise idiots are all
dead, then i'll formally raise my objection about Lisper's unfit
borrowing of the math symbol and term lambda.
(PS In America, imperative language programers are such not because
they prefer such methodology, but because they know shit.)
----------------------------------
Addendum, 2003-05, 2006-04.
Haskell logo
above: Haskell language's new logo, inargurated in 2003-05. Superb!
Haskell logo Haskell logo
above: Two Web logos for Haskell.
Someone has written a C++ library for functional programing, called
FC++. (by Brian McNamara and Yannis Smaragdakis, 2003) Their website is
http://www.cc.gatech.edu/~yannis/fc++/index.html. They have unsettled
logos. Here's one of them:
FC++ logo
There's a Scheme-to-C compiler called Chicken (by Felix L Winkelmann,
at http://www.call-with-current-continuation.org/chicken.html).
Scheme Chicken logo
This is getting silly and disrespectful.
----
This post is archived at:
http://xahlee.org/UnixResource_dir/lambda_logo.html
PS if you know any new lambda logo, please let me know. Thanks.
Xah
···@xahlee.org
∑ http://xahlee.org/
I bet the ∑-book also has some λ-stuff in it. If it doesn't, it
probably uses some other greek letters that aren't mentioned on the
cover. It's such a shame, really ... :(
--
Lars Rune Nøstdal
http://lars.nostdal.org/
Scripsit "Xah Lee" <···@xahlee.org>
> Subroutines in lisps easily have side-effects, and sometimes
> non-functional programing methodologies such as OOP are actually
> encouraged in lisp. As most of you know, the lambda symbol chosen by
> functional languages is to signify no side-effects.
What are you smoking? You're sure you could stop anytime you wanted,
right?
--
Henning Makholm "What a hideous colour khaki is."
> In this respect, i
> find the lisp languages not totally deserving the use of lambda in
> their logo.
Lisp was the first language to prove the practical usefulness of the
lambda calculus, so from a historical perspective, I don't believe ANY
other language deserves the use of this symbol more...
Of course the side effects are not included into the theory to keep it
simple, but the lisp language is a superset of lambda calculus (you can
write completely functional - so maybe it should be called lambda++
> Although i have these minor objections with lispers using the lambda
> symbol, but overall i think the lispers and i share a more important
> common goal. That is, to kill all imperative programing ignoramuses of
> the world.
If that was Lisp's goal, it would probably be spelled H-A-S-K-E-L-L
One goal of Lisp is ultimate abstraction, which is often achieved
through functional style - but sometimes your problem domains demand
other paradigms like oop or declarative constructs like prolog offers.
So, Lisp is rather a meta-language that helps building an extensible
compiler for ANY language you want to design on top of it. But, as
everything will run on a Turing-machine in the end, it is necessary to
have side-effects on a low-level. Haskell uses side-effects, too, but
they are hidden from the programmer, which means that it's impossible to
optimize certain abstractions...
> Once the unix and c and perl and otherwise idiots are all
> dead, then i'll formally raise my objection about Lisper's unfit
> borrowing of the math symbol and term lambda.
If you don't know that there are problem domains where these languages
are by far more useful that a pure functional one, your horizon isn't
much wider than that of the silliest Java hacker you know...
Xah Lee wrote:
> PS if you know any new lambda logo, please let me know. Thanks.
^
Oops, no, that would be an old lambda logo...
--
David Hopwood <····················@blueyonder.co.uk>
Xah Lee wrote:
> A Lambda Logo Tour
> (and why LISP languages using λ as logo should not be looked upon
> kindly)
>
> Xah Lee, 2002-02
>
> Dear lispers,
For the love of Java! Where is the Java in this post?
Underwear related off topic trivia:
At university we worked out that Y-fronts weren't Y-fronts at all -
after all, the 'Y' is upside down - they're actually lambda pants.