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Please help us with our research....
by Mini Haskell 16 Mar '01

16 Mar '01

Hi We are a small group of undergraduate computer science students from the University of Nottingham. As part of our second year we have been assigned to do a software engineering group project. The project put us together as a group and we were told what we had to do, our instructions were as follows: Mini Haskell ------------ The aim of this project is to build an interpreter for a small functional programming language called Mini Haskell. For simplicity, the only values in the language will be integers, lists, and functions. As well as allowing expressions to be evaluated to a final result, the interpreter should also allow the individual steps in the evaluation process to be seen. ------------ AS part of our research we have developed an on-line questionnaire which looks at the importance of some of the ideas we have had for the project. The questionnaire is found on our website and asks some very simple multiple choice questions which should take no longer than 2 minutes to complete. Please help us by looking at the site and by filling in our questionnaire in the feedback section. Please go to questionnaire: http://quest.minihaskell.com website: http://www.minihaskell.com thankyou for your time Dave - minihaskell _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

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Ghc / Hugs inconsistencty.
by Grace Trigue White 15 Mar '01

15 Mar '01

The following program compiles under ghc, but hugs complains that there is an unexpected keyword "forall" on the line defining the type X. The type used is the type of the primitive runST, so it is a valid type. It seems that one should be able to create a type synonym for it. The situation is unchanged if the type X is given a parameter a, i.e. "type X a = (forall s. ST s a) -> a". module Main where import ST type Module s a = ST s a type X = (forall s. ST s a) -> a f :: (forall s. ST s a) -> a f x = undefined --type ModuleConnect = forall s. (forall t. ST (s, t) a) -> ST s a main :: IO () main = do { putStrLn "Hello World!!!" }

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DEADLINE EXTENSION: ESSLLI'01 Workshop on Semantic Knowledge Acquisition and Categorisation (Helsinki, Finland)
by Ahti Pietarinen 15 Mar '01

15 Mar '01

*************** EXTENDED DEADLINE **************** ----- NEW DEADLINE: APRIL 23rd ----- ----- Please check new dates below! ----- SEMANTIC KNOWLEDGE ACQUISITION AND CATEGORISATION Workshop at ESSLLI XIII (Helsinki, Finland) Helsinki, Finland, August 13th - 17th 2001 Workshop home page http://www.ilc.pi.cnr.it/~esslli ESSLLI 2001 home page http://www.helsinki.fi/esslli ------------------------------------------------------------------- Endorsed by SIGSEM, the ACL Special Interest Group on computational semantics ------------------------------------------------------------------- The sheer amount of knowledge necessary to shed light on the way word meanings mutually relate in context or distribute in lexico-semantic classes appears to exceed the limits of human conscious awareness and descriptive capability. Particularly at this level of linguistic analysis, then, we seem to be in need of automatic ways of filtering, structuring and classifying semantic evidence through inspection of a large number of word uses in context. Totally or partially unsupervised inductive methods of knowledge acquisition from corpus data are credited with being able to provide such ways. Yet, it remains to be seen how acquired information can best be represented in current formal models for knowledge representation, for it to be made available to mainstream NLP applications. There are reasons to believe that this integration will require much more than a simple extension of off-the-shelf machine learning technology. At the same time, any major breakthrough in this area is bound to have significant repercussions on the way word meanings and lexico-semantic classes in general are formally represented and used for applications. With these purposes in mind, the workshop intends to focus on the issue of interaction between techniques for inducing semantic information from corpus data and formal methods of linguistic knowledge representation. In particular, we encourage in-depth analysis of underlying assumptions of the proposed techniques and methods and discussion of possible relevant connections with cognitive, linguistic,logical and philosophical issues. TOPICS OF INTEREST Possible themes for contributions are: - development of 'data-driven' semantic type systems - dynamic update and tuning of formal ontologies with text data - 'hybrid models' of knowledge extraction, whereby machine learning methods are integrated with formal structures of knowledge representation - creation of dynamic lexical knowledge-bases - formal representation and structuring of the flow of information extracted from texts. WORKSHOP ORGANISATION The workshop will be held on five subsequent days, August 13th-17th 2001. It will take place during the ESSLLI-Summer School in Helsinki, and will be open to all members of the LLI-community, computational linguistics and cognitive science as well. Each session will consist of two talks plus discussion (30mins + 15mins each). The workshop language will be English. ---------------------------------------------------------------------------- GUIDELINES FOR SUBMISSIONS The organizers welcome contributions from different fields of computational linguistics, logic and cognitive science. 1. Submissions will consist of full papers reporting on original, unpublished works. Papers should not exceed 5000 words (including references), must contain a 5-10 lines abstract, and must be submitted in postscript format 2. The reviewing of papers will be blind. Hence the paper should not include the authors' names and affiliations. Furthermore, self-references that reveal the author's identity should be avoided. 3. Identification information will be put in a separate file consisting of: Title of the paper: Author(s): Affiliation(s): E-mail(s): Abstract: 4. Submitted papers and identification information must be sent to the following address by APRIL 23rd 2001: esslli2001(a)ilc.pi.cnr.it Accepted papers will be notified by MAY 15th, together with the comments of the reviewers. The final version of the papers will be prepared in LaTeX by JUNE 15th, for publication in the Workshop proceedings. The stylesheet will be circulated in due time. Note that all workshop participants must register as participants of ESSLLI. The early registration fees apply to authors of accepted papers. --------------------------------------------------------------------------- IMPORTANT DATES April 23rd 2001 - Deadline for submitting papers May 15th 2001 - Notification of acceptance June 15th 2001 - Preparation of the final version of the paper June 30th 2001 - Final program of the workshop August 13th 2001 - The workshop begins --------------------------------------------------------------------------- PROGRAM COMMITEE Ted Briscoe (Cambridge University, Cambridge, United Kingdom) Nicoletta Calzolari (Istituto di Linguistica Computazionale, CNR, Pisa, Italy) Christiane Fellbaum (Princeton University, Princeton, USA) Ed Hovy (USC, Marina del Rey CA, USA) Dekang Lin (University of Alberta, Edmonton, Canada) Antonio Sanfilippo (LingoMotors Inc., Cambridge MA, USA) Piek Vossen (SAILLABS, Antwerpen, The Netherlands) ORGANISING COMMITEE Alessandro Lenci Simonetta Montemagni Vito Pirrelli Istituto di Linguistica Computazionale (ILC) - CNR Area della Ricerca CNR Via Alfieri 1 (San Cataldo) I-56010 PISA Italy WORKSHOP CONTACT ADDRESS esslli2001(a)ilc.pi.cnr.it http://www.ilc.pi.cnr.it/~esslli ESSLLI 2001 CONTACT ADDRESS esslli(a)helsinki.fi http://www.helsinki.fi/esslli --------------------------------------------------------------------------

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CfP: Babel01 Workshop on Multi-Language Infrastructure and Interoperability
by Nick Benton 14 Mar '01

14 Mar '01

BABEL'01 CALL FOR PAPERS First Workshop on Multi-Language Infrastructure and Interoperability http://research.microsoft.com/~nick/babel01.htm Satellite to PLI'01 Firenze, Italy, 8th September 2001 AIMS AND SCOPE Recent years have seen a resurgence of interest in multi-language tools and intermediate languages, and in interoperability between programs and components written in different programming languages. Shared infrastructure such as code generators, analysis tools and garbage collectors can greatly ease the task of producing a high-quality implementation of a new programming language, whilst being able to interoperate easily with code written in existing languages is essential for such an implementation to be useful in practice. This workshop aims to bring together researchers and developers working on multi-language integration. Contributions are welcome on topics including, but not limited to: * Compilation of high level languages to common executable formats such as Sun's Java Virtual Machine, the DRA's ANDF or Microsoft's .NET Common Language Runtime. * Defining and using bindings for component middleware such as OMG's CORBA or Microsoft's COM. * Language constructs to support interoperability between different languages, particularly from different paradigms (e.g. OO/functional). * Multi-language backends for compilation and/or analysis (e.g. MLRISC, FLINT, C--, TAL, SUIF). * Type theoretic and semantic foundations for multi-language work. * Multi-language development environments and tools (e.g. debuggers, profilers). Submissions may address any programming paradigm. Experience papers which describe the use of multiple languages in application development are also welcome. Authors unsure of the appropriateness of a potential submission should email the PC chair (nick(a)microsoft.com) PROGRAMME COMMITTEE Nick Benton (chair) Microsoft Research Fergus Henderson University of Melbourne Andrew Kennedy (organiser) Microsoft Research Greg Morrisett Cornell University Martin Odersky Ecole Polytechnique Federale de Lausanne John Reppy Bell Labs Andrew Tolmach Portland State University David Wakeling University of Exeter INVITED SPEAKERS Zhong Shao Yale University IMPORTANT DATES Deadline for submission 1st June 2001 Notification of acceptance 9th July 2001 Final version due 10th August 2001 SUBMISSION DETAILS Papers should be at most 14 pages and should be submitted in Ghostscript-compatible PostScript or PDF format and be printable on both US letter and A4 paper. Authors are strongly encouraged to use ENTCS style files (see http://math.tulane.edu/~entcs/) Papers should be submitted electronically from the workshop website given above. Submissions should not overlap significantly with work which has already been published or submitted to any other conference or journal. An informal proceedings will be published as a technical report and distributed at the workshop. It is intended that a final proceedings will be published in a volume of ENTCS.

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DEADLINE EXTENSION: Logic & Games ESSLLI'01 workshop
by Ahti Pietarinen 14 Mar '01

14 Mar '01

- Apologies for multiple copies - Please note: DEADLINE EXTENSION for Logic & Games ESSLLI 2001 workshop 20-24 August, Helsinki University, Finland !!!!! New Deadline is: April 9, 2001 !!!!! %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% %% Call for Papers %% %% %% %% ESSLLI Workshop on Logic and Games %% %% %% %% %% %% August 20-24, 2001 %% %% Helsinki, Finland %% %% %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% GENERAL INFORMATION: Games have been utilized within logic for a variety of different purposes such as semantic evaluation games, model comparison games, and proof games. On the other hand, logic has become increasingly important in game theory, in particular for the epistemic foundation of game-theoretic solution concepts. As the TARK (http://www.tark.org) and LOFT (http://www.econ.ucdavis.edu/ faculty/bonanno/loft4.html) conferences show, interaction between logic and game theory has become more diverse in recent years, exploring game logics, the use of game-theory in multi-agent systems, game-theoretic accounts of natural language phenomena, and the role of language in defining preferences. The workshop is part of the 13th European Summer School in Logic, Language and Information (ESSLLI) which takes place at the University of Helsinki from August 13 until August 24, 2001 (http://www.helsinki.fi/esslli) The workshop aims to provide a forum for advanced Ph.D. students and other researchers from game theory and logic to present their research on (1) game- theoretic techniques applied to logic, and (2) logical models or analyses of games and game-theoretic problems. We specifically invite presentations in any of the following areas: 1) Logical analysis of games, e.g. modeling knowledge, belief, and information flow in games; applications of epistemic and dynamic logic to games 2) Logic games, e.g. model comparison games, semantic evaluation games, Independence-friendly logic 3) Game logics, e.g. extensions of program logics and modal logics to investigate the structure of games in general 4) The role of language and logical definability in games, and connections between natural language and games generally 5) Logical approaches to multi-agent systems with a special focus on game-theoretic aspects SUBMISSION GUIDELINES: Papers should not exceed 15 pages in length. A postscript or pdf version of the paper should be submitted by e-mail to BOTH organizers before the deadline given below. Note that all workshop contributors must register for the summer school. ORGANISERS: Marc Pauly Gabriel Sandu CWI Department of Philosophy P.O. Box 94079 P.O. 24 (Unioninkatu 40) 1090 GB Amsterdam 00014 University of Helsinki The Netherlands Finland E-mail: pauly(a)cwi.nl E-mail: Sandu(a)elo.helsinki.fi IMPORTANT DATES: Submission deadline: April 9, 2001 Notification of contributors: May 1, 2001 Final version due: June 1, 2001 Workshop Dates: August 20-24, 2001 ================================================================

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RE: Contexts in Existential Types
by Simon Peyton-Jones 14 Mar '01

14 Mar '01

Yes, with your modification, it works just fine in GHC, and I guess therefore hbc. Documentatino in the user manual. http://haskell.cs.yale.edu/ghc/ Simon | -----Original Message----- | From: Ashley Yakeley [mailto:ashley@semantic.org] | Sent: 14 March 2001 04:22 | To: Haskell List | Subject: Re: Contexts in Existential Types | | | At 2001-03-13 19:36, I wrote: | | >Would it be appropriate for Haskell to be able to remember | contexts in | >existential types? For instance, currently this does not | work in Hugs: | > | >-- | >class Charable a where | > obtainChar :: a -> Char | > | >instance Charable Char where | > obtainChar c = c | > | >data AnyCharable = forall c. (Charable c) => MkAnyCharable c | > | >anyA = MkAnyCharable 'a' | >recoverA = obtainChar ((\(MkAnyCharable c) -> c) anyA) | >-- | | Whoops, my error. It is possible to do this: | | -- | recoverA = (\(MkAnyCharable c) -> obtainChar c) anyA | -- | | Sorry... | | -- | Ashley Yakeley, Seattle WA | | | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell |

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Contexts in Existential Types
by Ashley Yakeley 13 Mar '01

13 Mar '01

Would it be appropriate for Haskell to be able to remember contexts in existential types? For instance, currently this does not work in Hugs: -- class Charable a where obtainChar :: a -> Char instance Charable Char where obtainChar c = c data AnyCharable = forall c. (Charable c) => MkAnyCharable c anyA = MkAnyCharable 'a' recoverA = obtainChar ((\(MkAnyCharable c) -> c) anyA) -- I believe allowing it to work would not amount to storing dynamic type information. Is this an overlooked hole or would it break the spirit of the language? -- Ashley Yakeley, Seattle WA

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Re: Contexts in Existential Types
by Ashley Yakeley 13 Mar '01

13 Mar '01

At 2001-03-13 19:36, I wrote: >Would it be appropriate for Haskell to be able to remember contexts in >existential types? For instance, currently this does not work in Hugs: > >-- >class Charable a where > obtainChar :: a -> Char > >instance Charable Char where > obtainChar c = c > >data AnyCharable = forall c. (Charable c) => MkAnyCharable c > >anyA = MkAnyCharable 'a' >recoverA = obtainChar ((\(MkAnyCharable c) -> c) anyA) >-- Whoops, my error. It is possible to do this: -- recoverA = (\(MkAnyCharable c) -> obtainChar c) anyA -- Sorry... -- Ashley Yakeley, Seattle WA

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quantum search algorithm
by Jan Skibinski 13 Mar '01

13 Mar '01

Directly from the oven :-): http://www.numeric-quest.com/haskell/QuantumSearch.hs Excerpt from a short module description is given below. Jan Grover's algorithm assumes that one is given a quantum function, also called an oracle, that indicates, when confronted with any number between 0 and N-1, whether this number is or is not the special number being sought. The algorithm enables one to find a marked item in unstructured N-item database in a time that scales not as N, as a classical computer would require, but only as sqrt N. Putting it another way: the maximum number of calls to oracle is proportional to sqrt N. Think about a scenario when the oracle charges you per call, or when its computations are very lengthy. The answer is probabilistic, but given with very high degree of probability. In our implementation the 'search' function is able to find specifically marked number from the assemble of 8 numbers: 0..7 in just two calls to oracle, with very high degree of probability. The 'test' performs m such searches. Note that the final stage of the search is simulated as a quantum measurement performed on the state vector.

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Laws for Monad and MonadPlus.
by Theodore Norvell 13 Mar '01

13 Mar '01

Hi all. I was revising a short article I've written about Monads in Haskell and started wondering about the identities associated with Monads. I think it is generally agreed (and in the report) that the following identities should be true of a Monad: Left identity: return a >>= k = k a Right identity: p >>= return = p Associativity: (p >>= j) >= k = p >>= (\x->(j x >>= k)) [provided x is not free in j or k] What about MonadPlus? By analogy with semirings, I came up with: Zero: mzero >>= k = mzero = p >>= (\x -> mzero) Identity: p `mplus` mzero = p = mzero `mplus` p Commutativity: p `mplus` q = q `mplus` p Right distributivity: (p `mplus` q) >>= k = (p >>= k) `mplus` (q >>= k) Left distributivity: p >>= (\x->j x `mplus` k x) = (p >>= j) `mplus` (p >== k) [provided x is not free in j or k] But commutativity does not hold for Maybe or [], left distributivity does not hold for Maybe and right distributivity does not hold for [], so these can't be right. Are the other identities I've listed ok? Are there other identities that I've missed? Cheers, Theodore Norvell ---------------------------- Dr. Theodore Norvell theo(a)engr.mun.ca Electrical and Computer Engineering http://www.engr.mun.ca/~theo Engineering and Applied Science Phone: (709) 737-8962 Memorial University of Newfoundland Fax: (709) 737-4042 St. John's, NF, Canada, A1B 3X5

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