Subject: Jobs at Macquarie Date: Mon, 11 Mar 91 09:52:09 EST From: street@mqcomp.mqcs.mq.oz.au (Ross Street) Jobs at Macquarie I just obtained the ad for 3 positions in our department; they're hot off the press. You at least need a PhD in math & a strong & continuing research record. Also experience & interest in teaching. As you know, we are fairly strong in category theory (joined by our nearby colleagues at Sydney); number theory (van der Poorten, Loxton), and functional analysis & pde's (Alan Mc Intosh) make up our three strong groups. TECHNICAL DETAILS: Reference 650323: fixed-term for an analyst in preference (still worth trying). Reference 910090: fixed-term for either mathematical computing person or one experienced in teaching large classes. Reference 890464: tenurable, in one of our existing research fields (the competition will be strong). All available 1 July 1991 and fixed-terms are for 5 years (although it is possible to reapply for tenurable jobs later). Senior Lecturer $43584-$51015 ($Australian is around 76c US at present) Lecturer $33163-$34584 Send your application(s) to Academic Staff Office Macquarie University N S W 2109 AUSTRALIA. Deadline 30 April 1991. They will probably send you a summary application for to fill out once you make first contact which you could do on their FAX 61-2-8057398. Best of luck. ................ Perhaps I should remind people of the category theorists at Macquarie other than myself: Murray Adelman, Brian Day (part-time), Michael Johnson, Robin Cockett (unfortunately leaving for Calgary in June), and frequent visitors. Also there is active interest amongst the computer scientists in category theory (Mike has at least one paper with some of them). Best regards, Ross Subject: Release 2.0 Date: Sun, 10 Mar 91 15:27:15 PST From: Vaughan Pratt ======================================== An apparently empty message was sent yesterday - the mailer problem that caused it is not worth decribing. Herewith the message. Bob Rosebrugh ======================================== Structures Directory -- Email addresses of structure theorists Release 2.0, March 10, 1991 Master copy: Boole.Stanford.EDU:^ftp/pub/struct.dir Maintainer: Vaughan Pratt, pratt@cs.stanford.edu This is an email directory of logicians, algebraists, and programming linguists working primarily on structural problems in mathematics and computer science. It is organized as a Unix aliases file and may be appended directly to the aliases file that normally resides in /usr/lib or /etc. The most recent release of this directory may be obtained at any time by anonymous ftp from Boole.Stanford.EDU as the file /pub/struct.dir The purpose of this directory is to permit those listed in it to be easily contacted individually by email. NOTICE: Please do not use any email address obtained from this directory for other than the purpose stated above without first obtaining the consent of the owner of that address. Such proscribed uses include adding an address obtained from this directory to a mailing list used for broadcast mailings, and noting the fact of inclusion in this directory in a profile of the included individual. The list observes the following conventions. Column 1 is the alias, which usually consists of the surname prefixed when necessary for disambiguation with an initial or the whole first name. It starts in character column 1 and is restricted to the 26 characters a-z (no capitals, digits, or punctuation), and usually includes any preceding "de" or "van". Column 2, which starts in character column 17, is the email address in lower case with no %'s, and is either a regular internet domain address, a .bitnet address, or a uucp address in ! format. Column 3 is "(Forename" and column 4 the matching "Surname)". The list is sorted by surname using the Unix sort command in the form `sort +3` (sort ignoring the first three columns). The "de" or "van" if any is placed in whichever of columnn 3 or 4 achieves its owner's preferred alphabetization. Column 3 starts as close to column 57 as possible subject to the other constraints and column 4 is separated from column 3 by one space. There are no tabs in the file, and no line is longer than 79 characters. Although the directory contains no repeated aliases (column 1 entries), the aliases file to which you append it may already contain aliases that also appear here. You should be aware that the resulting conflicts will not be reported as such, but rather that the mailing programs will select either the last or first repeated alias as the one to use depending respectively on whether or not your mail system preprocesses the aliases file for faster retrieval. Vaughan Pratt Computer Science Department Stanford University Stanford, CA 94305 pratt@cs.stanford.edu 415-723-2943 abadi: ma@src.dec.com (Martin Abadi) abramsky: sa@doc.ic.ac.uk (Samson Abramsky) aceto: luca@cogs.sussex.ac.uk (Luca Aceto) adams: useradms@mtsg.ubc.ca (Bob Adams) adler: ara@lom1.math.yale.edu (Alan Adler) aitchison: iain@mundoe.munnari.oz (Iain Aitchison) amadio: amadio@dmi.ens.fr (Roberto Amadio) ambler: sja@cs.qmw.ac.uk (Simon Ambler) anderson: anderson@bright.math.uoregon.edu (Frank Anderson) apt: apt@cs.utexas.edu (Krzystof Apt) artemov: art@log.mian.su (Sergei Artemov) astesiano: astes@igecuniv.bitnet (Egidio Astesiano) atkinson: atkinson@math.toronto.edu (Derek Atkinson) avron: aa@taurus.bitnet (Arnon Avron) bach: rene@tech.ascom.ch (Rene Bach) baker: kab@math.ucla.edu (Kirby Baker) baranoff: sergei@hm.iias.spb.su (Sergei Baranoff) barr: barr@triples.math.mcgill.ca (Michael Barr) bartle: rgb@math.ams.com (Bob Bartle) barwise: barwise@iuvax.cs.indiana.edu (Jon Barwise) beeson: beeson@ucscc.ucsc.edu (Michael Beeson) beigel: beigel-richard@cs.yale.edu (Richard Beigel) bellin: glb@lfcs.edinburgh.ac.uk (Gian-Luigi Bellin) benson: dbenson@eecs.wsu.edu (David Benson) vanbenthem: johan@fwi.uva.nl (Johan.van Benthem) bergman: gbergman@cartan.berkeley.edu (George Bergman) bergstra: madelon@fwi.uva.nl (Jan Bergstra) berry: mirsa.inria.fr (Gerard Berry) betti: betti@unimat.to.cnr.it (Renato Betti) bhadhuri: pbhaduri@cs2.cs.wsu.edu (Purandar Bhadhuri) bier: eric_bier.parc@xerox.com (Eric Bier) birtwistle: graham@cpsc.ucalgary.ca (Graham Birtwistle) blair: ziggy@hx.lcs.mit.edu (Michael Blair) blass: blass@ub.cc.umich.edu (Andreas Blass) bbloom: bard@cs.cornell.edu (Bard Bloom) sbloom: sbloom@sitvxa.bitnet (Steve Bloom) lblum: lblum@ernie.berkeley.edu (Lenore Blum) mblum: blum@ernie.berkeley.edu (Manuel Blum) vanemdeboas: pveb@cwi.nl (Peter.van.Emde Boas) boehm: boehm.pa@xerox.com (Hans Boehm) bonacina: bonacina@sbcs.sunysb.edu (M.Paola Bonacina) boolos: boolos@athena.mit.edu (George Boolos) borceux: fborceux@buclln11.bitnet (Francis Borceux) jborwein: jborwein@cs.dal.ca (Jon Borwein) pborwein: pborwein@cs.dal.ca (Peter Borwein) bouchard: eomsg@acadvm1.uottawa.ca (Monique Bouchard) boyer: boyer@cli.com (Bob Boyer) breazu: val@linc.cis.upenn.edu (Val Breazu-Tannen) breen: udos001@frors12.bitnet (Larry Breen) brink: chrikey1.ucthpx@f4.n494.z5.fidonet.org (Chris Brink) brinkman: mabrink@dknkurz1.bitnet (Hans-Berndt Brinkman) brookes: brookes@b.gp.cs.cmu.edu (Steve Brookes) brown: r.brown@vaxa.bangor.ac.uk (Ronnie Brown) broy: broy@lan.informatik.tu-muenchen.dbp.de (Manfred Broy) bruce: kim@cs.williams.edu (Kim Bruce) brunner: hbrunner@mun.bitnet (Herman Brunner) debukh: ecomail@vms2.uni-c.dk (Per.de Bukh) bullejos: mbullejos@ugr.es (Manuel Bullejos) (bunge: bunge@triples.math.mcgill.ca also.works.for.Marta Bunge) bunge: inbe@musicb.mcgill.ca (Marta Bunge) burroni: burroni@frmap711.bitnet (Albert Burroni) burstall: rb@lfcs.ed.ac.uk (Rod Burstall) buss: sbuss@cs.ucsd.edu (Sam Buss) cannon: cannon_j@maths.su.oz.au (John Cannon) carboni: carboni@imiucca.unimi.it (Aurelio Carboni) cardelli: luca@src.dec.com (Luca Cardelli) carr: carrdm@snyplaba.bitnet (Donna Carr) carter: nicola@mcgill1.bitnet (Nicola Carter) cartwright: cork@rice.edu (Corky Cartwright) casley: casley@cs.stanford.edu (Ross Casley) chandra: ashok@ibm.com (Ashok Chandra) chen: chen@pchu.depaul.edu (Andy Chen) choi: choi@grad1.cis.upenn.edu (Jin-Young Choi) chou: chou@rascal.ics.utexas.edu (Shang-Ching Chou) chu: chu@ace.bsd.uchicago.edu (Po-Hsiang Chu) clarke: clarke@a.cs.cmu.edu (Ed Clarke) cockett: rcockett@mqccsuna.mqcc.mq.oz.au (Robin Cockett) cocquand: coquande@margaux.inria.fr (Thierry Cocquand) cohen: avrac@computer-lab.cambridge.ac.uk (Avra Cohen) comer: comers@citadel.bitnet (Stephen Comer) cowen: mthmjc@ubvms.bitnet (Mike Cowen) crew: crew@cs.stanford.edu (Roger Crew) crossley: jnc@bruce.cs.monash.oz.au (John Crossley) crow: crow@csl.sri.com (Judy Crow) curien: curien@dmi.ens.fr (Pierre-Louis Curien) davey: davey@latcs1.lat.oz.au (Brian Davey) davis: davism@acf4.nyu.edu (Martin Davis) dawson: rdawson@husky1.stmarys.ca (Robert Dawson) degano: degano@di.unipi.it (Pier-Paolo Degano) delfour: delfour@cc.umontreal.ca (Michel Delfour) diaconescu: rdcbb@cunyvm.bitnet (Radu Diaconescu) diekert: diekert@informatik.tu-muenchen.dbp.de (Volker Diekert) diers: diers@frcitl81.bitnet (Yves Diers) doh: doh@ksuvax1.cis.ksu.edu (Kyung-Goo Doh) doob: mdoob@ccu.umanitoba.ca (Michael Doob) duba: duba@rice.edu (Bruce Duba) dubey: rdubey@yoda.eecs.wsu.edu (Rakesh Dubey) dubuc: dcfden!edubuc@mate.edu.ar (Eduardo Dubuc) duggan: den@cs.umd.edu (Dominic Duggan) dunn: dunn@iuvax.cs.indiana.edu (Mike Dunn) duskin: mthduskn@ubvms.bitnet (Jack Duskin) dybkjaer: dybkjaer@diku.dk (Hans Dybkjaer) ehresmann: ehres@frmap711.bitnet (Andree Ehresmann) ehrhard: ehrhard@ens.fr (Thomas Ehrhard) ehrlich: ehrlich@inria.inria.fr (Bobby Ehrlich) vaneijck: jve@cwi.nl (Jan.van Eijck) emerson: a.emerson@cs.utexas.edu (Alan Emerson) enderton: hbe@math.ucla.edu (Herb Enderton) zenith: zenith@ensmp.fr (Steven Ericsson-Zenith) ernst: mernst@theory.lcs.mit.edu (Michael Ernst) fagin: fagin@ibm.com (Ron Fagin) faro: v068p76v@ubvmsa.bitnet (Emilio Faro) fasel: jhf@lanl.gov (Joe Fasel) feferman: sf@csli.stanford.edu (Sol Feferman) feigenbaum: jf@research.att.com (Joan Feigenbaum) feldman: d_feldman@unhh.bitnet (David Feldman) ferguson: mike@tel.inrs.cdn (Michael Ferguson) finkelstein: stacy@saul.cis.upenn.edu (Stacy Finkelstein) fischer: fischer-michael@yale.edu (Mike Fischer) floyd: floyd@cs.stanford.edu (Bob Floyd) foo: norman@cs.su.oz.au (Norman Foo) fourman: mikef@lfcs.edinburgh.ac.uk (Michael Fourman) fox: fox@triples.math.mcgill.ca (Thomas Fox) freese: ralph@kahuna.math.hawaii.edu (Ralph Freese) frei: bitnet.arfr@ubcmtsg (Armin Frei) freire: freire@euscvx.decnet.cern (J.L. Freire.Nistal) freyd: pjf@linc.cis.upenn.edu (Peter Freyd) pamfreyd: pam@linc.cis.upenn.edu (Pam Freyd) fritsch: rudolf.fritsch@mathematik.uni-muenchen.dbp.de (Rudolph Fritsch) gago: alzzs002@seins.santiago.usc.es (Felipe Gago) gaifman: gaifman@humus.huji.ac.il (Haim Gaifman) ganong: ganong@yorkvm1.bitnet (Richard Ganong) vangelder: avg@cs.ucsc.edu (Allen.Van Gelder) genrich: gsfp03@dbngmd21.bitnet (Hartmann Genrich) geramita: anthony.v.geramita@queensu.ca (Anthony Geramita) gerstenhaber: gersten@penndrls.bitnet (Murray Gerstenhaber) gerth: wsinrobg@eutrc3.urc.tue.nl (Rob Gerth) gischer: gischer@cs.wm.edu (Jay Gischer) givant: givant@mills.berkeley.edu (Steve Givant) vanglabbeek: rvg@cs.stanford.edu (Rob.van Glabbeek) goguen: joseph.goguen@prg.oxford.ac.uk (Joseph Goguen) bgoldberg: goldberg@cs.nyu.edu (Ben Goldberg) jgoldberg: phr00jg@technion.bitnet (Jacques Goldberg) goltz: gf1018@dbngmd21.bitnet (Ulla Goltz) goodaire: edgar@munucs.mun.ca (Edgar Goodaire) gordon: v5200e@templevm.bitnet (Bob Gordon) gratzer: gratzer@uofmcc.bitnet (George Graetzer) grandis: grandis@igecuniv.bitnet (Marco Grandis) gray: gray@math.uiuc.edu (John Gray) grove: grove@cs.stanford.edu (Adam Grove) gruska: gruska@rosun1.informatik.uni-hamburg.de (Jozef Gruska) guessarian: ig@litp.ibp.fr (Irene Guessarian) guitart: guitart@frmap711.bitnet (Rene Guitart) cgunter: gunter@central.cis.upenn.edu (Carl Gunter) egunter: elsa@research.att.com (Elsa Gunter) gupta: vgupta@cs.stanford.edu (Vineet Gupta) gurevich: gurevich@dip.eecs.umich.edu (Yuri Gurevich) dhalpern: jdan@sun.com (Dan Halpern) jhalpern: halpern@ibm.com (Joe Halpern) hanna: fkh@ukc.ac.uk (Keith Hanna) hardie: hardieka.uctvax@f4.n494.z5.fidonet.org (Kieth Hardie) harel: harel@wisdom.weizmann.ac.il (David Harel) harland: jah@mullauna.cs.mu.oz.au (James Harland) harper: rwh@proof.ergo.cs.cmu.edu (Robert Harper) hart: wiawkph@hdetud1.bitnet (Klaas Hart) haveraaen: magne@eik.ii.uib.no (Magne Haveraaen) hebert: mhebert@lavalvm1.bitnet (Michel Hebert) heckmann: heckmann@cs.uni-sb.de (Reinhold Heckmann) hennessy: matthewh@cogs.sussex.ac.uk (Matthew Hennessy) henrickson: henriksen@ymir.bitnet (Mel Henrickson) henzinger: tah@cs.stanford.edu (Tom Henzinger) herz: in3u@mcgillb.bitnet (Carl Herz) hill: whill@hplwlh.hpl.hp.com (Walt Hill) hindley: majrh@pyr.swan.ac.uk (Roger Hindley) hoare: julie@prg.oxford.ac.uk (Tony Hoare) hoehnke: gabi@opal.cs.tu-berlin.de (Hans-Jurgen Hoehnke) hoofman: raymond@cs.ruu.nl (Raymond Hoofman) hook: hook@cse.ogi.edu (James Hook) hopcroft: jeh@cs.cornell.edu (John Hopcroft) hosek: dhosek@hmcvax.bitnet (Don Hosek) hsiang: hsiang@sbcs.sunysb.edu (Jieh Hsiang) hudak: hudak@cs.yale.edu (Paul Hudak) huet: huet@inria.inria.fr (Gerard Huet) husberg: nhu@dione.hut.fi (Nisse Husberg) huth: mrh@tulmath.math.tulane.edu (Michael Huth) hyland: jmeh@phoenix.cambridge.ac.uk (J.M.E. Hyland) istrail: sistrail@eagle.wesleyan.edu (Soren Istrail) ito: ito@ito.ecei.tohoku.junet (Takayasu Ito) jacobs: bart@cs.kun.nl (Bart Jacobs) jaffar: joxan@ibm.com (Joxan Jaffar) jagadeesan: radha@cs.cornell.edu (Radha Jagadeesan) janssen: theo@fwi.uva.nl (Theo Janssen) jardine: jardine@uwovax.uwo.ca (John Jardine) jay: cbj@lfcs.edinburgh.ac.uk (Barry Jay) jeffrey: alan.jeffrey@prg.oxford.ac.uk (Alan Jeffrey) jenkins: maj@qucis.bitnet (Mike Jenkins) mjohnson: johnson_m@maths.su.oz.au (Mike Johnson) pjohnson: pjohnson@eagle.wesleyan.edu (Paul Johnson) jonsson: jonssob@vuctrvax.bitnet (Bjarni Jonsson) jouvelot: jouvelot@ensmp.fr (Pierre Jouvelot) joyal: joyal@math.uqam.ca (Andre Joyal) joyce: djoyce@clarku.bitnet (David Joyce) jung: xmatdb5r@ddathd21.bitnet (Achim Jung) kahn: kahn@mirsa.inria.fr (Gilles Kahn) kane: kane@uwovax.uwo.ca (Richard Kane) kao: kao@iuvax.cs.indiana.edu (Ming Kao) karp: karp@ernie.berkeley.edu (Dick Karp) kasangian: kasan@imiucca.unimu.it (Stefano Kasangian) kelly: kelly_m@maths.su.oz.au (Max Kelly) kennaway: jrk@sys.uea.ac.uk (Richard Kennaway) kennison: jkennison@clarku (John Kennison) kfoury: kfoury@bu-cs.bu.edu (Dennis Kfoury) kiehn: kiehn@lan.informatik.tu-muenchen.dbp.de (Astrid Kiehn) klarlund: klarlund@cs.cornell.edu (Nils Klarlund) kleisli: kleisli@cfruni52.bitnet (Heinrich Kleisli) klop: jwk@cwi.nl (Jan Klop) knijnenburg: peterk@cs.ruu.nl (Peter Knijnenburg) kochman: kochman@nexus.yorku.ca (Stanley Kochman) kock: matak@mi.aau.dk (Anders Kock) kolaitis: kolaitis@cs.ucsc.edu (Phokion Kolaitis) koslowski: koslowj@math.ksu.edu (Juergen Koslowski) kozen: kozen@cs.cornell.edu (Dexter Kozen) kwiatkowska: mzk@leicester.ac.uk (Marta Kwiatkowska) labute: labute@gauss.math.mcgill.ca (John Labute) ladkin: ladkin@icsib8.berkeley.edu (Peter Ladkin) ladner: ladner@cs.washington.edu (Richard Ladner) lafont: lafont@frulm63.bitnet (Yves Lafont) lamarche: lamarche@cs.dal.ca (Francois Lamarche) lambek: lambek@triples.math.mcgill.ca (Joachim Lambek) lampe: lampe@kahuna.math.hawaii.edu (Bill Lampe) lamport: lamport@src.dec.com (Leslie Lamport) latch: dml@bklyncis.bitnet (Dana Latch) launchbury: jl@cs.glasgow.ac.uk (John Launchbury) lawvere: mthmjc@ubvm.cc.buffalo.edu (Bill Lawvere) leavens: leavens@bambam.cs.iastate.edu (Gary Leavens) leivant: daniel.leivant@b.gp.cs.cmu.edu (Daniel Leivant) lent: aflent@theory.lcs.mit.edu (Arthur Lent) levin: lnd@cs.bu.edu (Leonid Levin) lewis: lglewis@sunrise.bitnet (Gaunce Lewis) liao: aliao@eagle.wesleyan.edu (Andrew Liao) libkin: libkin@saul.cis.upenn.edu (Leonid Libkin) lilius: jli@dione.hut.fi (Johan Lilius) lincoln: lincoln@cs.stanford.edu (Pat Lincoln) linton: flinton@eagle.wesleyan.edu (Fred Linton) longo: longo@dmi.ens.fr (Giuseppe Longo) lord: hlord@csupomona.edu (Harriet Lord) loui: mloui@note.nsf.gov (Michael Loui) lowry: lowry@kestrel.edu (Mike Lowry) lubarsky: r_lubarsky@faudm.bitnet (Robert Lubarsky) lubliner: coby@ucbcevax.bitnet (Coby Lubliner) luckham: dcl@anna.stanford.edu (David Luckham) lynch: lynch@holmes.lcs.mit.edu (Nancy Lynch) mercouroff: nm@cs.brandeis.edu (Nicolas Mercouroff) ma: qingming.ma@cs.cmu.edu (Qingming Ma) macdonald: macstone@bdc.ubc.ca (John MacDonald) mackenzie: pm1kchm@primea.sheffield.ac.uk (K.Charles.H. Mackenzie) macon: nmacon@nsf.gov (Nat Macon) macqueen: macqueen@research.att.com (David Macqueen) maddux: s1.rdm@isumvs.bitnet (Roger Maddux) madhav: madhav@neon.stanford.edu (Neel Madhav) main: main@boulder.colorado.edu (Michael Main) majid: shm10@phx.cam.ac.uk (Shahn Majid) makkai: makkai@triples.math.mcgill.ca (Michael Makkai) manna: manna@cs.stanford.edu (Zohar Manna) marden: marden@iassns.bitnet (Al Marden) marti-oliet: narciso@csl.sri.com (Narciso Marti-Oliet) martini: martini@di.unipi.it (Simone Martini) mauri: mauri@imiucca.unimi.it (Giancarlo Mauri) mccoll: wfm@prg.oxford.ac.uk (Bill McColl) mckay: mckay@conu1.bitnet (John McKay) mckay: wendy@cc.umontreal.ca (Wendy McKay) mcnulty: n410102@univscvm.bitnet (George McNulty) mcrobbie: mam@arp.anu.oz.au (Michael McRobbie) melton: austin@cis.ksu.edu (Austin Melton) meseguer: meseguer@csl.sri.com (Jose Meseguer) meyer: meyer@theory.lcs.mit.edu (Albert Meyer) milner: rm@lfcs.ed.ac.uk (Robin Milner) mislove: mwm@tulmath.math.tulane.edu (Michael Mislove) misra: misra@cs.utexas.edu (Jay Misra) mitchell: jcm@cs.stanford.edu (John Mitchell) mochnacki: stefan@centaur.astro.utoronto.ca (Stefan Mochnacki) moggi: em@lfcs.ed.ac.uk (Eugenio Moggi) molnar: rkm@macalstr.bitnet (Richard Molnar) monro: monro_g@maths.su.oz.au (Gordon Monro) montanari: ugo@di.unipi.it (Ugo Montanari) demoor: Oege.de.Moor@prg.oxford.ac.uk (Oege.de Moor) moschovakis: ynm@math.ucla.edu (Yiannis Moschovakis) muller: muller@harvard.edu (Robert Muller) mulry: phil@colgate.edu (Phil Mulry) mulvey: mmfc6@cluster.sussex.ac.uk (Chris Mulvey) mumford: mumford@zariski.harvard.edu (David Mumford) murphy: dvjm@cs.glasgow.ac.uk (David Murphy) murthy: murthy@cs.cornell.edu (Chet Murthy) murty: mt88@mcgilla.bitnet (Ram Murty) nation: nation@kahuna.math.hawaii.edu (James.B. Nation) nelson: nealn@cse.ogi.edu (Neal Nelson) nickau: nickau@hrz.uni-siegen.dbp.de (? Nickau) denicola: denicola@icnucevm.bitnet (Rocco.De Nicola) niefield: niefiels@union.bitnet (Susan Niefield) nowakowski: rjn@cs.dal.ca (Richard Nowakowski) ohearn: ohearn@top.cis.syr.edu (Peter Ohearn) okada: okada@concour.cs.concordia.ca (Mitsu Okada) oles: oles@ibm.com (Frank Oles) ong: chlo@doc.ic.ac.uk (Luke Ong) orzech: orzechm@qucdn.bitnet (Morris Orzech) otto: james_jim_otto@cup.portal.com (Jim Otto) overbeek: overbeek@anl-mcs.arpa (Russ Overbeek) depaiva: valeria.paiva@cl.cam.ac.uk (Valeria.de Paiva) panangaden: prakash@opus.cs.mcgill.ca (Prakash Panangaden) papert: seymour@media-lab.media.mit.edu (Seymour Papert) pare: pare@cs.dal.ca (Bob Pare) parikh: ripbc@cunyvm.bitnet (Rohit Parikh) parker: stott@cs.ucla.edu (Stott Parker) paterson: msp@cs.warwick.ac.uk (Mike Paterson) paulson: lcp@cl.cam.ac.uk (Larry Paulson) pavlovic: pavlovic@math.ruu.nl (Dusko Pavlovic) pedicchio: ti2tsg24@icineca2.bitnet (Cristina Pedicchio) pelletier: jwpell@yorkvm1.bitnet (Joan Pelletier) penon: penon@frmap711.bitnet (Jean Penon) phillips: phillips@uvvm.bitnet (John Phillips) pierce: benjamin.pierce@proof.ergo.cs.cmu.edu (Benjamin Pierce) pigozzi: s2.dlp@isumvs.bitnet (Don Pigozzi) pinter: pinter-shlomit@yale.edu (Shlomit Pinter) pitt: dhp@cs.surrey.ac.uk (David Pitt) pitts: ap@cl.cam.ac.uk (Andy Pitts) plaisted: plaisted@cs.unc.edu (David Plaisted) platek: richard@oracorp.com (Richard Platek) platt: platt@uofmcc.bitnet (Craig Platt) plotkin: gdp@lfcs.edinburgh.ac.uk (Gordon Plotkin) pnueli: amir@wisdom.weizmann.ac.il (Amir Pnueli) poigne: ap@gmdzi.gmd.de (Axel Poigne) poirot: poirot@boole.stanford.edu (Hercule Poirot) porst: porst@ubrinf.uucp (H.-E. Porst) porter: mas013@vaxc.bangor.ac.uk (Tim Porter) power: ajp@lfcs.edinburgh.ac.uk (John Power) pratt: pratt@cs.stanford.edu (Vaughan Pratt) priestley: hap@vax.oxford.ac.uk (Hilary Priestley) probst: probst@bond.crim.ca (Richard Probst) proute: ap@frmap711.bitnet (Alain Proute) quackenbush: bquack@ccm.umanitoba.ca (Bob Quackenbush) rabin: rabin@humus.huji.ac.il (Michael Rabin) rachev: zarirach@bernoulli.ucsb.edu (Zari Rachev) ramshaw: ramshaw@src.dec.com (Lyle Ramshaw) randall: randall@elbereth.rutgers.edu (John Randall) raphael: raphael@vax2.concordia.ca (Robert Raphael) rattray: cr@cs.stir.ac.uk (Charles Rattray) repin: repin@log.mian.su (Nikolai Repin) reyes: 241@umtlvr.bitnet (Gonzalo Reyes) reynolds: john.reynolds@c.cs.cmu.edu (John Reynolds) riecke: riecke@theory.lcs.mit.edu (Jon Riecke) riemens: sriemens@ualtavm.bitnet (Sherman Riemenschneider) ritter: er@cl.cam.ac.uk (Eike Ritter) erobinson: edmundr@cogs.susx.ac.uk (Edmund Robinson) krobinson: kenr@elecvac.oz.au (Ken Robinson) deroever: wsinwpr@eutrc3.urc.tue.nl (Willem.de Roever) rolfsen: userodin@ubcmtsg.bitnet (Dale Rolfsen) roman: imate@unamvm1.bitnet (Leopoldo Roman) rosebrugh: rrosebrugh@mta.bitnet (Bob Rosebrugh) rosenthal: rosenthk@union.bitnet (Kimmo Rosenthal) rosolini: matema2@ipruniv.bitnet (Pino Rosolini) rota: rota@math.mit.edu (Gian-Carlo Rota) rotman: symcom!rotman@uxc.cso.uiuc.edu (Joseph Rotman) rounds: bill_rounds@um.cc.umich.edu (Bill Rounds) rovan: uniba!rovan@relay.eu.net (Branislav Rovan) rozenberg: rozenber@hlerul5.bitnet (Grzegor Rozenberg) rozenfeld: ar@alv.umd.edu (Azriel Rozenfeld) rudich: arie@theory.lcs.mit.edu (Arie Rudich) rudie: rudie@ecfb.toronto.edu (Karen Rudie) ruitenburg: wimr@math.mscs.mu.edu (Wim Ruitenburg) rumbos: rumbos@unamvm1.bitnet (Beatriz Rumbos) rus: rus@herky.cs.uiowa.edu (Theodor Rus) rutten: janr@piring.cwi.nl (Jan Rutten) rydeheard: david@r3.cs.man.ac.uk (David Rydeheard) sakurai: a87480@tansei.cc.u-tokyo.ac.jp (Takafumi Sakurai) salisbury: salt@yorkvm1.bitnet (Tom Salisbury) sankappanevar: sankah@snynewba.bitnet (Hanamantagouda.P. Sankappanevar) sannella: dsannella@lfcs.ed.ac.uk (Don Sannella) sato: schuko@sun4.cc.kyushu-u.ac.jp (Hiroyuki Sato) scedrov: andre@cis.upenn.edu (Andre Scedrov) schelter: wfs@cli.com (Bill Schelter) schmidt: jschmidt@daimi.dk (Jorn Schmidt) schroeppel: rcs@la.tis.com (Rich Schroeppel) schumacher: schu@acadia.bitnet (Dietmar Schumacher) dscott: dana.scott@c.cs.cmu.edu (Dana Scott) pscott: scpsg@acadvm1.uottawa.ca (Phil Scott) seely: rags@bruce.cs.monash.oz.au (Robert Seely) seldin: seldin@antares.concordia.ca (Jonathan Seldin) shankar: shankar@csl.sri.com (Natarajan Shankar) shapiro: udi@wisdom.bitnet (Udi Shapiro) shields: m.shields@cs.surrey.ac.uk (Mike Shields) sichler: sichler@ccm.umanitoba.ca (Jiri Sichler) kurt: sieber@fb10vax.informatik.uni-saarland.dbp.de (Kurt Sieber) isimon: isimon@brusp.bitnet (Imre Simon) slifker: slifker@svax.cs.cornell.edu (Michael Slifker) smaill: smaill@aipna.edinburgh.ac.uk (Alan Smaill) small: nwnexus!cjsa!jeff@uunet.uu.net (Jeffery Small) gsmith: dalcs!gretchen@uunet.uu.net (Gretchen Smith) ssmith: scott@cs.jhu.edu (Scott Smith) sobral: sobral@ciuc2.uc.rccn.pt (Manuela Sobral) spencer: dwights@cse.ogi.edu (Dwight Spencer) srinivas: srinivas@madeleine.ics.uci.edu (Yellamraju Srinivas) staples: staples@uqcspe.cs.uq.oz.au (John Staples) stark: stark@cs.sunysb.edu (Eugene Stark) steele: steele@think.com (Guy Steele) steiner: maths@vme.gla.ac.uk (Richard Steiner) stell: john@cs.kl.ac.uk (John Stell) stewart: cstewart@watserv1.uwaterloo.ca (Cameron Stewart) astone: macstone@bdc.ubc.ca (Art Stone) stoughton: allen@cogs.sussex.ac.uk (Allen Stoughton) stout: lnstout@uiucvmd.bitnet (Lawrence Stout) strecker: strecker@galois.math.ksu.edu (George Strecker) street: street@mqcomp.mqcs.mq.oz.au (Ross Street) streicher: streiche@unipas.fmi.uni-passau.de (Thomas Streicher) subrahmanyam: ramesh@linc.cis.upenn.edu (Ramesh Subrahmanyam) sun: yong@minster.york.ac.uk (Yong Sun) suppes: suppes@csli.stanford.edu (Pat Suppes) swaminathan: swami@cs.dal.ca (S. Swaminathan) szabo: szabof@conu1.bitnet (Fred Szabo) takayama: takayama@okilab.oki.co.jp (Yukihide Takayama) talcott: clt@sail.stanford.edu (Carolyn Talcott) tatsuta: tatsuta@sato.riec.tohoku.ac.jp (Makoto Tatsuta) taubner: taubner@lan.informatik.tu-muenchen.dbp.de (Dirk Taubner) paultaylor: pt@doc.ic.ac.uk (Paul Taylor) philiptaylor: p.taylor@vax.rhbnc.ac.uk (Philip Taylor) wtaylor: wtaylor@boulder.colorado.edu (Walt Taylor) tennent: rdt@qucis.queensu.ca (Bob Tennent) tholen: tholen@yorkvm1.bitnet (Walter Tholen) thomson: tom@nw.stl.stc.co.uk (Tom Thomson) thurston: wpt@math.princeton.edu (Bill Thurston) tiuryn: tiuryn@cs.bu.edu (Jerzy Tiuryn) trakhtenbrot: trakhte@taurus.bitnet (Boris Trakhtenbrot) tschantz: tschanst@vuctrvax.bitnet (Steve Tschantz) tsuiki: tsuiki@kurims.kyoto-u.ac.jp (Hideki Tsuiki) turbak: lyn@zurich.ai.mit.edu (Franklyn Turbak) urquhart: urquhart@ai.toronto.edu (Alasdair Urquhart) valeriote: valeriot@mcmaster.bitnet (Matt Valeriote) van: d_vanosdol@unhh.unh.edu (Osdol Van) vanosdol: d_vanosdol@unhh.unh.edu (Donovan Van.Osdol) vardi: vardi@almaden.bitnet (Moishe Vardi) vermeulen: jjcvmath.uctvax@f4.n494.z5.fidonet.org (Japie Vermeulen) verwer: nico@cs.ruu.nl (Nico Verwer) vickers: sjv@doc.ic.ac.uk (Steven Vickers) vitanyi: paulv@cwi.nl (Paul Vitanyi) devries: ferjan@cwi.nl (Fer-jan.de Vries) waarts: orli@cs.stanford.edu (Orli Waarts) wachter: wachter@itd.nrl.navy.mil (Ralph Wachter) wadler: wadler@cs.glasgow.ac.uk (Philip Wadler) wagner: wagner@ibm.com (Eric Wagner) wallen: lincoln.wallen@prg.oxford.ac.uk (Lincoln Wallen) walters: walters_b@maths.su.oz.au (Bob Walters) wand: wand@corwin.ccs.northeastern.edu (Mitchell Wand) wasilewska: anita@sbcs.sunysb.edu (Anita Wasilewska) wells: cfw2@po.cwru.edu (Charles Wells) wendt: wendt@cs.dal.ca (Michael Wendt) white: bwhite@inmet.inmet.com (Bill White) williams: ewilliam@kean.ucs.mun.ca (Ed Williams) winkler: winkler@csl.sri.com (Timothy Winkler) wood: rjwood@cs.dal.ca (Richard Wood) wraith: gavinw@sussex.ac.uk (Gavin Wraith) wright: gpwsg@acadvm1.uottawa.ca (Graham Wright) wyler: wyler@cs.cmu.edu (Oswald Wyler) yardini: eyal@wisdom.weizmann.ac.il (Eyal Yardini) yarroll: piggy@gargoyle.uchicago.edu (La.Monte Yarroll) yetter: dyetter@msri.org (David Yetter) yoshida: yoshida@icot.jp (Kaoru Yoshida) yoshiki: yoshiki@etl.go.jp (Kinoshita Yoshiki) young: young@xx.lcs.mit.edu (Jonathan Young) zawadowski: warsaw@ccb.uib.es (Marek Zawadowski) zhang: gqz@pollux.cs.uga.edu (Qiang Zhang) zocco: dean.zocco@klb (Meg Zocco) Subject: Comments on Release 2.0 Date: Wed, 13 Mar 91 12:27:21 PST From: Vaughan Pratt You should have just received a copy of release 2.0 of the Structures Directory, email addresses of "structure theorists". In order to get it past his mailer Bob has edited out the # (sharp) sign found at the beginning of each of the first 55 lines. If you are following the directions to append this file to your aliases file (found in /usr/lib or /etc) then you will need to either delete or comment out those 55 lines. To comment them out to match the source code insert a sharp sign at the start of each of the 55 lines. An alternative that I have not tried but that I would expect to work is to put a left parenthesis at the start of line 1 and a right parenthesis at the end of line 55 or on line 56 (blank). This is an alternative method of "commenting out" text in aliases files. The only problems I can imagine this causing are excessive length of commented-out region (unlikely provided the commented-out text is being scanned by a finite-state automaton), and failure to handle nested parentheses correctly (the commented-out text includes several parenthetical remarks). If you encounter these or any other problems please contact me, pratt@cs.stanford.edu. Note also that the character on line 3 immediately before the ftp is a tilde, not a caret as it may have appeared on your machine. To retrieve the latest release of this list at any time use anonymous ftp to fetch the file /pub/structdir from Boole.Stanford.EDU (at internet address 36.8.0.65 if your name server claims ignorance of 19th century logicians.) Vaughan Pratt Subject: Scott topologies Date: 13-MAR-1991 17:11:03.00 From: "P. B. Johnson" Given a locale A, one may endow the set of points Loc(1,A) with the relative topology enherited from A, (and thereby produce the "spatial part of A"). Or, viewing Loc(1,A) as a poset with directed sups (in the "specialization" ordering), one may equip Loc(1,A) with the Scott topology. I have convinced myself that for arbitrary A, the Scott topology is at least as fine as the relative topology. Are there conditions on the locale A which characterize the coincidence of these two ways one might topologize its set of points? Paul Subject: Applications of Grothendieck topologies in computer science Date: Wed, 13 Mar 91 16:37:01 -0800 From: Y V Srinivas I am currently completing a dissertation in which I derive a general pattern matching algorithm using Grothendieck topologies. For the related work section, I am looking for other applications in computer science of Grothendieck topologies or sheaf theory. I already have the following references: Michel Eytan's PhD thesis (which applies Grothendieck topologies to grammars), and Monteiro and Pereira's paper on modeling concurrency using sheaves. If you know of any other applications, could you please send me a message? The abstract of my dissertation is enclosed. The dissertation will be ready for distribution in early April. If you would like a copy, please let me know. - srinivas PATTERN MATCHING: A SHEAF-THEORETIC APPROACH Yellamraju V. Srinivas PhD Dissertation (forthcoming March 1991) University of California, Irvine SUMMARY: A general theory of pattern matching is presented by adopting an extensional, geometric view of patterns. The extension of the matching relation consists of the occurrences of all possible patterns in a particular target. The geometry of the pattern describes the structure of the pattern and the spatial relationships among parts of the pattern. The extension and the geometry, when combined, produce a structure called a sheaf. Sheaf theory is a well developed branch of mathematics which studies the global consequences of locally defined properties. For pattern matching, an occurrence of a pattern, a global property of the pattern, is obtained by gluing together occurrences of parts of the pattern, which are locally defined properties. A sheaf-theoretic view of pattern matching provides a uniform treatment of pattern matching on any kind of data structure---strings, trees, graphs, hypergraphs, and so on. Such a parametric description is achieved by using the language of category theory, a highly abstract description of commonly occurring structures and relationships in mathematics. A generalized version of the Knuth-Morris-Pratt pattern matching algorithm is derived by gradually converting the extensional description of pattern matching as a sheaf into an intensional description. The algorithm results from a synergy of four very general program synthesis/transformation techniques: (1) Divide and conquer: exploit the sheaf condition; assemble a full match by gluing together partial matches; (2) Finite differencing: collect and update partial matches incrementally while traversing the target; (3) Backtracking: instead of saving all partial matches, save just one; when this partial match cannot be extended, fail back to another; (4) Partial evaluation: precompute pattern-based (and therefore constant) computations into an automaton. The derivation is carried out in a general framework using Grothendieck topologies. By appropriately instantiating the underlying data structures and topologies, the same scheme results in matching algorithms for patterns with variables and with multiple patterns. Slight variations of the derivation result in Earley's algorithm for context-free parsing, LR parsing, and Waltz filtering, a relaxation algorithm for providing 3-D interpretations to 2-D images. Other applications of a geometric view of patterns are briefly considered: rewrites, parallel algorithms, induction and computability. ======== Y. V. Srinivas E-mail: srinivas@ics.uci.edu Information and Computer Science University of California Irvine, CA 92717, USA Subject: Re: Scott topologies Date: 15 Mar 91 10:54 From: Steven John Vickers "The Scott topology is at least as fine as the relative topology." This is Corollary 7.3.2 in my book "Topology via Logic". "Are there conditions characterizing the coincidence of the two topologies on the points of a locale A?" I suspect that results such as Johnstone's "Scott is not always sober" might make exact characterizations difficult. Also, as stated in the original question, the characterization would have to include all locales without any points, so perhaps the class is not a terribly natural one to consider. Of course, a useful sufficient condition is for A to be completely distributive as a frame, this corresponding spatially to Scott topologies on continuous posets. (See Johnstone's "Stone Spaces".) Steve Vickers Subject: Applications of Grothendieck topologies in computer science From: Date: 16 Mar 91 12:49 Dear Srinivas, I have done some work along the lines that you mention. An abstract of one paper is appended below, and a citation to a second. I could send you copies if you like. There is also some work on sheaf theoretic semantics of digital circuits in preparation (with Victoria Stavridou and others) but not yet finished. I'd love a copy of your dissertation. Cheers, Joseph 00000000000000000000000000000000000000000000000000000000000000000000000000000 Semantics of Concurrent Interacting Objects using Sheaf Theory Joseph A. Goguen Sheaf theory was developed in mathematics to study relationships between local and global phenomena in analysis and geometry. This talk uses sheaf theory to explicate phenomena in concurrent systems, including object, active object, inheritance, deadlock, real time interaction, and security. This approach can then be applied to give semantics for object oriented languages and systems. 00000000000000000000000000000000000000000000000000000000000000000000000000000 @incollection(ehrich-goguen-sernadas91, title = "A Categorical Theory of Objects as Observed Processes", author = "Hans-Dieter Ehrich and Joseph Goguen and Amilcar Sernadas", booktitle = "Proceedings, {REX/FOOL} Workshop on Foundations of Object Oriented Languages", publisher = "Springer", year = 1991, editors = "J.W. deBakker and Gregorz Rozenberg", pages = "to appear", note = "Lecture Notes in Computer Science") Subject: Material available from Sydney by anonymous ftp Date: Mon, 18 Mar 91 15:53:16 +10 From: walters_b@maths.su.oz.au (Bob Walters) SYDNEY CATEGORY THEORY SEMINAR Category theory material Available by Anonymous FTP from maths.su.oz.au This file is README in the sydcat directory of maths.su.oz.au, 129.78.68.2, accessible by anonymous ftp. The sydcat directory is for FTP distribution of recent publications and other material of the Sydney Category Theory Group. The Sydney Category Theory Group consists of mathematicians and students at the University of Sydney and Macquarie University, Sydney, Australia including the following: Murray Adelman Sean Carmody carmody_s@maths.su.oz.au Brian Day Robin Cockett rcockett@mqccsuna.mqcc.mq.oz.au Robbie Gates gates_r@maths.su.oz.au Mike Johnson johnson_m@maths.su.oz.au Giulio Katis katis_p@maths.su.oz.au Max Kelly kelly_m@maths.su.oz.au Stephen Lack lack@maths.su.oz.au Stephen Ma ma_s@maths.su.oz.au Wafaa Moynham moynham_w@maths.su.oz.au Wesley Phoa phoa_w@maths.su.oz.au Ross Street street@mqcomp.mqcs.mq.oz.au Sun Shu-Hao sun_s@maths.su.oz.au Bob Walters walters_b@maths.su.oz.au ==========================Instructions====================================== FTP LOGIN. Give the following commands. ftp maths.su.oz.au Login: anonymous (if you don't have an account on maths) Paswd: yoursurname (though any string will work) bin (if you are retrieving a .dvi file) prompt off (if you want no ? prompts from mget) cd sydcat (change directory to _public/sydcat ls -lt (see what's there, most recent first) mget filename-1 ... filename-n (e.g. mget catcurrent.Z) quit (exit from FTP) DVI. If you wish to print paper, calg say, retrieve calg.dvi and associated .eps and .sty files from the subdirectory calg (cd calg first). You must first give the bin command to ftp since .dvi files are not text files. You will then need a dvi to postscript converter which will include the .eps files. Print the resulting postscript file on your host. PROBLEMS. If you have problems in either retrieving or compiling papers, please contact Bob Walters. NOTE. Please note that the IP satellite link between Australia and the rest of the world is saturated most of the time. Large file transfers to non-Australian sites should be spaced out, and should preferably take place between the hours 2300 and 0800 local Eastern Australian time (the local time appears in the ftpd banner at connection). ===========================Available papers================================= The following files and directories are available: catcurrent The Category Theory address list maintained by Max Kelly and Michael Johnson Updated 2 Jan 1991 catcurrent.Z Compressed version of catcurrent email Vaughan Pratt's latest email address list Updated 10 March 1991 como A directory containing como.dvi and some associated postscript files for the paper: S. Carmody, R.F.C. Walters, Computing quotients of actions of a free category. calg A directory containing calg.dvi and some associated postscript files for the paper: S. Carmody, R.F.C. Walters, The Todd-Coxeter Procedure and Left Kan Extensions. sydcat A directory containing sydcat.tex and macros. sydcat.tex is a listing of seminars given at the Sydney Category Seminar Updated 18 March 1991 cics A directory containing cics.tex and macros. cics.tex is a listing of seminars given at the Sydney Categories in Computer Science Seminar. Updated 18 March 1991 -- Bob Walters Department of Pure Mathematics, University of Sydney, NSW 2006, Australia Internet: walters_b@maths.su.oz.au Phone: +61 2 692 2966 FAX: +61 2 692 4534 ============================================================================ Subject: More references on sheaves in concurrency Date: Mon, 18 Mar 91 14:23:46 PST From: Vaughan Pratt The earliest application of sheaf theory to concurrency I am aware of is the LICS'86 paper of Monteiro and Pereira: @InProceedings( MP, Author="Monteiro, L.F. and Pereira, F.C.N.", Title="Outline of a Sheaf-theoretic Approach to Concurrency", Booktitle="Proc. IEEE Symp. on Logic in Computer Science", Address="Boston", Month=Jul, Year=1986) My IJPP paper in the same year, @Article( Pr86, Author="Pratt, V.R.", Title="Modeling Concurrency with Partial Orders", Journal="Int. J. of Parallel Programming", Volume=15, Number=1, Pages="33-71", Month=Feb, Year=1986) (retrievable from boole.stanford.edu by anonymous ftp as /pub/ijpp.tex, see also the README in the same directory.) discusses the relationship of my semantics of networks (section 4 of my paper) with Monteiro and Pereira's semantics. Ignore the February 1986 date on that issue of IJPP, I did not send the manuscript to IJPP until after LICS'86. This permitted me to read Monteiro and Pereira's paper and address the question of what differences if any there were between my treatment and their sheaf-theoretic one. I covered this in two paragraphs (appended here) giving respectively the similarities and the differences, the latter in terms of changes sufficient to bring my treatment into juxtaposition with theirs. It may well be however that these differences are artifacts of too narrow a notion of sheaf. If the definition in my paper can be viewed as sheaf-theoretic without making those changes I would appreciate hearing the details from anyone with the requisite sheaf theory and a willingess to sort out the definitions in the respective papers. I have not worked enough with sheaves myself to trust my judgement on this. Vaughan Pratt ==========2 paragraphs on sheaves from "Modelling Concurrency with PO's"=== This approach has some important points in common with our approach, as well as some important differences. The points of correspondence are as follows. In place of a category of open sets of a topological space $X$ and their inclusions we use the category {\bf Set} whose objects (sets) provide our alphabets and whose morphisms (functions) our translations. By using arbitrary functions rather than inclusions we provide for action renaming (via non-inclusions) and ``short-circuiting'' (via non-injections). The concept of restriction has the same significance for both approaches, and is a contravariant functor in both cases. The explicit concept of section agreement on intersections, which is the essence of a sheaf, appears only implicitly in our approach, by virtue of the possibility of overlap between the $t_i(\Sigma_i)$'s. We do not require the $t_i(\Sigma_i)$'s to cover $\Sigma$, but then neither do we require that the system behavior consistent with a family of component behaviors be unique. In place of monoids we use processes made up of pomsets, which come with a built-in solution to the problem of non-injective translations and which also have the several advantages cited for them in the introduction, not achievable with monoids. Our approach may be massaged into closer correspondence with the sheaf approach by replacing the $\Sigma_i$'s with their images $t_i(\Sigma_i)$ as subsets of $\Sigma$, and the $t_i$'s with the corresponding inclusions from $t_i(\Sigma_i)$ into $\Sigma$, provided the $t_i$'s are injective and the $t_i(\Sigma_i)$'s cover $\Sigma$ (easily arranged by adding a dummy process to complete the cover). There is no loss of generality in requiring these subsets to be open since in the absence of other requirements $\Sigma$ can be equipped with the discrete topology (all subsets open). The information in the $P_i$'s is now not accessible since the $t_i$'s are gone, so, taking our sheaves to be sheaves of processes rather than of monoids, we move the $P_i$'s into the restriction functor by having $\rho$ map $t_i(\Sigma_i)$ to $t_i?+(P_i)$ where $t_i?+$ is the extension of $t_i$ to a pomset homomorphism. The remaining step is to have $\rho$ map the other subsets of $\Sigma$, or at least the arbitrary unions and finite intersections of the $t_i(\Sigma_i)$'s, to appropriate subsets of $\Sigma\ddagger$, in order to make $\rho$ into a sheaf, though we have not yet worked out the appropriate assignment. Subject: Re: Applications of Grothendieck topologies in computer science Date: 19 Mar 91 9:35 From: Steven John Vickers Grothendieck topologies in computer science You may be interested in my paper "Geometric theories and databases", which I shall be presenting at the LMS Symposium on Applications of Categories in Computer Science this July in Durham. (I can send you a draft if you wish.) Its abstract is - <<< Domain theoretic understanding of databases as elements of powerdomains is modified to allow multisets of records instead of sets. This is related to geometric theories and classifying toposes, and it is shown that algebraic base domains lead to algebraic categories of models in two cases analogous to the lower (Hoare) powerdomain and Gunter's mixed powerdomain. >>> The results amount to saying that certain Grothendieck toposes are equivalent. But the flavour of the paper is not to describe these toposes concretely as categories of sheaves over sites, but to specify them less directly as classifying toposes of geometric theories. I believe it is important to understand that this can be done, for the geometric theories provide a much defter way of talking about Grothendieck toposes. Hence I would hope that although the paper does not mention sheaves or Grothendieck topologies, you would find it very useful. Note that "algebraic categories of models" refers to theories whose classifying toposes are actually presheaf categories, with no Grothendieck topologies required. But the theories proved equivalent to these are not prima facie algebraic, and so the work yields completeness results for them. Finally, let me mention that an underlying theme of the work is that geometric logic is the logic of finite observations (as discussed in my book "Topology via Logic" in the propositional case), and that the methods developed go far deeper than the database applications. Steve Vickers. (And can you send me a copy of the dissertation, please?) Subject: Re: Applications of Grothendieck topologies in computer science Date: 20 Mar 91 10:27 From: John Launchbury X-Comment1: ############################################################# X-Comment2: # # X-Comment3: # uk.ac.glasgow.cs has changed to uk.ac.glasgow.dcs # X-Comment4: # # X-Comment5: ############################################################# Grothendieck topologies in computer science =========================================== In my thesis I use Grothendiek fibrations as a means of expressing the decomposition of Scott domains into dependent sums of fibres. The application area is Partial Evaluation. Domain projections are used to provide a description of what portion of a function's argument will be known during partial evaluation, and the fibres of the projection describe the possible freedom of the complete argument. This information is used to construct the run-time argument of the specialised version of the original function. The practical benefit of using fibrations is that certain previously ad hoc optimisations in Partial Evaluation arise directly from the theory. References to this work are: Projection Factorisations in Partial Evaluation, J.Launchbury, Ph.D. Thesis, Glasgow University, Nov 89. Distinguished Dissertations in Comp. Sci., Vol 1, C.U.P., due May 1991. Dependent Sums Express Separation of Binding Times, J.Launchbury, proc. Functional Programming, Glasgow, 1989, K.Davis and J.Hughes eds., Workshops in Computing, Springer-Verlag, 1990. Subject: Research position available Date: Thu, 28 Mar 91 15:22:43 GMT From: gdp@lfcs.edinburgh.ac.uk RESEARCH FELLOWSHIP available in the LABORATORY for FOUNDATIONS of COMPUTER SCIENCE (LFCS) Department of Computer Science UNIVERSITY of EDINBURGH on the project LOGICAL and SEMANTICAL FRAMEWORKS (UK SERC rolling grant) Main investigators: G. PLOTKIN and E. MOGGI starting date: BEFORE JANUARY 1992 duration: 2 YEARS salary: an appropriate point on the RA1A scale: 11,399 - 18,165 Pounds Sterling p.a. to carry out research on PROGRAM LOGIC AND SEMANTICS with particular emphasis on such topics as: - partiality, recursive definitions and inductive principles; - the monadic approach to denotational semantics and its extension to program logics; - a modular approach to programming language semantics and logics. LFCS provides a very stimulating research environment. It is active, not only in the area of logic and semantics, but also in most areas of Theoretical Computer Science. It also has a strong interest in the application of basic theory through the development of computer based tools and systems and by conducting studies in the formal analysis of and reasoning about computer systems. EC funding should be available for collaboration with Cambridge (A. Pitts) and Genova (E. Moggi) on the above research topics. --------------------------------------------------------------------------- The ideal candidate should have: - a Ph.D. in (Theoretical) Computer Science, - expertise in Denotational Semantics and Program Logics, - some knowledge of Category Theory and its applications to Logic and Programming Language Semantics. Applicants should send (by e-mail to George Cleland at glc@lfcs.edinburgh.ac.uk) - a cv, incuding publications and a statement of research interests - a list of referees (prefereably with e-mail addresses) FOR FURTHER INFORMATION CONTACT: gdp@lfcs.edinburgh.ac.uk or em@lfcs.edinburgh.ac.uk