Lambda the Ultimate

Dear all,

I am wondering whether it is appropriate to ask a naive technique question here,

Let's define the pre-equivalence relation as a relation which has the propriety
1) symmetry 2) reflexivity.
(Attention, the transitivity is not guaranteed)

Do you happen to know some theory/paper that has a detailed study to this structure? It is for me interesting because I am working on an abstract interpretation of sequences of pre=equivalence relation over a finite set.

Thanks for all your ideas.

Zell

Erik Meijer will be hosting a panel today at Microsoft's PDC. Panelists are Gilad Bracha, Mark S. Miller, Herb Sutter and Anders Hejlsberg. Also, Anders will be on Channel 9 Live today from 1PM - 2PM PST. You can ask him questions in real time via Twitter (@ch9Live).

You can also send questions to the panelists via the PDC media player. Yes, you'll have to install Silverlight, but you probably have installed third party browser plug-ins before. This shouldn't be a blocker...If you can make it past this simple requirement, then:

Go to the PDC10 web page to watch the live streams.

I trust this is not considered spam and that many of you would find the panel and Anders' sessions quite interesting in addition to interacting with the panelists in real time (and later, with Anders). Given the panelists, it will not be a product marketing exercise... Topics will be varied, yet focused on programming languages and Erik will do a stellar job of moderating.

In terms of Anders on C9 Live, he'll have some very interesting things to say today in his PDC session (which, like all sessions, will be streamed live). You'll probably have questions for him, so why not ask? You should watch his PDC session live beginning today at 11:30AM PST. Then, ask him questions at 1PM PST on C9 Live.

C

Conrad Barski's Lisp book, Land of Lisp, is out. There's an example chapter implementing a Hunt the Wumpus remake. The book was previously mentioned with an April's 1st special, War of the Worlds.

Comments? Critiques?

Blurb:

Lisp has been hailed as the world’s most powerful programming language, but its cryptic syntax and academic reputation can be enough to scare off even experienced programmers. Those dark days are finally over—Land of Lisp brings the power of functional programming to the people!

With his brilliantly quirky comics and out-of-this-world games, longtime Lisper Conrad Barski teaches you the mysteries of Common Lisp. You’ll start with the basics, like list manipulation, I/O, and recursion, then move on to more complex topics like macros, higher order programming, and domain-specific languages. Then, when your brain overheats, you can kick back with an action-packed comic book interlude!

Along the way you’ll create (and play) games like Wizard Adventure, a text adventure with a whiskey-soaked twist, and Grand Theft Wumpus, the most violent version of Hunt the Wumpus the world has ever seen.

You'll learn to:

* Master the quirks of Lisp’s syntax and semantics
* Write concise and elegant functional programs
* Use macros, create domain-specific languages, and learn other advanced Lisp techniques
* Create your own web server, and use it to play browser-based games
* Put your Lisp skills to the test by writing brain-melting games like Dice of Doom and Orc Battle

With Land of Lisp, the power of functional programming is yours to wield.