Copyright note: I have not transferred more than a one-time licence on any paper published since 1995, inclusive. (Despite the fact that my last two papers in JPAA assert copyright; they are lying.) I am the copyright owner and I hereby give permission to copy them. This does not include permission to plagiarize them. As for the earlier ones, it depends on the journal, but as far as I am concerned copying for personal use is fair use. The copyright to TTT is owned by Charles and me and we allow free distribution. The copyright to the Fine, Gillman and Lambek monograph is murkier. It was not copyright originally and was published by the McGill University Press, so it seems clear that the US copyright law does not apply. Fine is deceased and I could not find his descendants. Gillman and Lambek were happy to see the republication. Fine's heirs are welcome to all the money we get for it.

Michael Barr, Injectivity of the circle in locally compact abelian groups Unpublished. This gives all the details of the title statement, although it can be gleaned from the literature. (2022)

Michael Barr, John Kennison, and Robert Raphael,
Coequalizers and free triples, II.
Theory Appl. Categories, **34** (2019), 662–683.

Michael Barr, John Kennison, and Robert Raphael,
Contractible simplicial objects.
Comm. Math. Univ. Carol. **60** (2019), 473–495.

Michael Barr,
Topological *-autonomous categories, revisited. Tbilisi Math. J.,
**10.3**, 51–64 (2017). This is an updated version of Topological
*-autonomous categories,
Theory Appl. Categories, **16** (2006), 700–708. This paper
corrects
some errors, finishes some badly incomplete proofs, and adds some new
material that answers a question raised by André Joyal.

Michael Barr, John Kennison, and Robert Raphael,
On reflective and coreflective hulls.
Cahiers Topologie Géométrie Différentielle
Catégorique,
**56** (2015), 162–208.

Michael Barr, John Kennison, and Robert Raphael,
Limit closures of
classes of commutative rings. Theory Appl. Categories,
**30** (2015), 229–304.

Michael Barr, John Kennison, and Robert Raphael,
The $*$-autonomous
category of uniform sup semi-lattices. Theory Appl. Categories,
**27** (2012), 222–241.

Joachim Lambek, Michael Barr, John Kennison, and Robert Raphael,
Injective
hulls of partially ordered monoids. Theory Appl. Categories,
**26** (2012), 338–348.

Michael Barr, John Kennison, and Robert Raphael,
Countable meets in coherent spaces with applications to the
cyclic spectrum.
Theory Appl. Categories, **25** (2011), 508–232.

Michael Barr, John Kennison, and Robert Raphael,
Flows: cocyclic and almost cocyclic.
Theory Appl. Categories, **25** (2010), 490–507.

Michael Barr, John Kennison, and Robert Raphael,
On *-autonomous categories of topological modules.
Theory Appl. Categories, **24** (2010), 278–293.

Michael Barr, John Kennison, and Robert Raphael,
Isbell duality for modules. Theory Appl. Categories,
**22** (2009), 401–419.

Michael Barr, John Kennison, and Robert Raphael,
Searching for more absolute CR-epic spaces. Theory Appl. Categories,
**22** (2009), 54–76.

Michael Barr, John Kennison, and Robert Raphael,
Local extension of maps. New York J. Math.
**15** (2009), 254–264.

Alexandre Grothendieck, Some aspects of homological algebra. Translation by Marcia L. Barr and Michael Barr of, Sur quelques points d'algèbre homologique.

Michael Barr, On duality of topological abelian groups. Unpublished note.

Michael Barr, John Kennison, and Robert Raphael,
Isbell duality. Theory Appl. Categories,
**20** (2008), 504–542.

J. Lambek, Programs, Grammars, Arguments. Unpublished notes. (2007).

Michael Barr, John Kennison, and Robert Raphael,
On productively Lindelöf spaces. Scient. Math. Japon.
**65** (2007), 23–36.

Michael Barr, John Kennison, and Robert Raphael,
Searching for absolute CR-epic spaces. Canadian J. Math. **59**
(2007), 465–487.

Michael Barr,
Topological *-autonomous categories. Theory Appl. Categories,
**16** (2006), 700–708.

N. J. Fine, L. Gillman and J. Lambek, Rings of Quotients of Rings of Continuous Functions. Originally published by McGill University, 1965.

Michael Barr,
Absolute homology. Theory Appl. Categories, **14**, (2005),
53–59.

Michael Barr, Robert Raphael, and R. Grant Wood,
On CR-epic embeddings and absolute
CR-epic spaces. Can. J. Math. **57** (2005),
1121–1138.

Michael Barr,
On subpregroups of the Lambek pregroup. Theory Appl.
Categories, **12**, (2004), 262–269.

Michael Barr,
Michael Barr, The
Chu construction: history of an idea. Proceedings of a conference
on Chu categories, UC Santa-Barbara, 2002. Theory Appl. Categories,
**17**, (2006), 10–16.

Michael Barr,
Algebraic cohomology: the early days. Fields Institute
Communications, **42** (2004), 1–26.

Michael Barr,
On subpregroups of the Lambek pregroup. Abstract: To appear in
Lambekfestschrift. Full paper: Theory Appl. Categories, **12**
(2004), 262–269.

Michael Barr, Walter Burgess, and Robert Raphael,
Ring epimorphisms and *C(X)*.
Theory Appl. Categories, **11** (2003), 283–308.

Michael Barr, Rational Erdos numbers. An unpublished bit of amusement, written in 2003, suggesting a modification of the Erdos number to take account of multiple collaborations.

Michael Barr Acyclic Models. Amer. Math. Soc. (2002, rev. 2017), xii + 238 pages.

Michael Barr,
A duality on simplicial complexes. Georgian Math. J., **9**
(2002), 601–605.

Michael Barr,
HSP subcategories of Eilenberg-Moore algebras. Theory Appl.
Categories, **10** (2002), 461–468.

Michael Barr and Heinrich Kleisli,
On Mackey topologies in topological abelian
groups. Theory Appl. Categories, **8** (2001),
54–62.

Michael Barr,
On *-autonomous categories of topological vector spaces. Cahiers
Topologie Géométrie Différentielle Catégorique,
**41** (2000), 243–254.

Michael Barr and Charles Wells Category Theory for Computing Science. Reprinted by the Centre de Recherche Maththématique (Revised edition, 1999).

Michael Barr,
*-Autonomous categories: once more around the track. Theory Appl.
Categories, **6** (1999), 5–24.

Michael Barr and Heinrich Kleisli,
Topological balls. Cahiers Topologie Géométrie
Différentielle Catégorique, **40** (1999),
3–20.

Michael Barr,
The separated extensional Chu category. Theory Appl. Categories,
**4** (1998), 127–137.

Michael Barr,
Note on a theorem of Putnam's. Theory Appl. Categories, **3**
(1997), 45–49.

Michael Barr, Notes on Linear logic and *-autonomous categories and on Sketches. Technical report of the Electrotechnical Laboratory (computer language section), Tsukuba, Japan, 1997, 28 pages.

Michael Barr,
Separability of tensor in Chu categories of vector spaces.
Math. Structures Comp. Sci., **6**
(1996), 213–217.

Michael Barr,
The Chu construction. Theory Appl. Categories, **2** (1996),
17–35.

Michael Barr,
Acyclic models. Canadian J. Math.,
**48** (1996), 258–273.

Michael Barr,
Cartan-Eilenberg cohomology and triples. J. Pure Applied Algebra,
**112** (1996), 219–238.

Michael Barr,
*-Autonomous categories, revisited. J. Pure Applied Algebra,
**111** (1996), 1–20.

Michael Barr,
Fuzzy models of linear logic. Math. Structures Comp. Sci., **6**
(1996), 301–312.

Michael Barr,
Oriented singular homology. Theory Appl. Categories, **1**
(1995), 1–9.

Michael Barr and M.C. Pedicchio,
Top^{op} is a quasi-variety. Cahiers
Topologie Géométrie Différentielle Catégorique, **36**
(1995), 3–11.

Michael Barr,
Non-symmetric *-autonomous categories. Theoretical Computer
Science, **139** (1995), 115–130.

Michael Barr,
Functorial semantics and HSP type theorems. Algebra Universalis,
**31** (1994), 223–241.

Michael Barr,
Terminal coalgebras for endofunctors on sets. Theoretical Comp.
Sci., **114** (1993), 299–315.

Michael Barr,
Algebraically compact functors. J. Pure Appl. Algebra, **82**
(1992), 211–232.

Michael Barr,
HSP type theorems in the category of posets. Proc. 7th
International Conf. Mathematical Foundation of Programming Language
Semantics, Lecture Notes in Computer Science, **598** (1992),
221–234.

Michael Barr,
*-Autonomous categories and linear logic. Math. Structures Comp.
Sci., **1** (1991), 159–178.

Michael Barr, Functional set theory. Unpublished. (Chandler Davis, editor of the Intelligencer, commissioned this paper, after hearing me mouth off about the paper referred to. He ``virtually'' (his word) guaranteed publication, although he could not actually guarantee it, which I understood. Not only didn't he ever publish it, he never had the courtesy to tell me that, but let the passage of time, now well over a decade, carry out this task.)

Michael Barr,
Fixed points in cartesian closed categories. Theoretical Comp.
Sci., **70** (1990), 65–72.

Michael Barr,
Accessible categories and models of linear logic. J. Pure Appl.
Algebra, **69** (1990), 219–232.

Michael Barr,
Models of Horn theories.
In J. W. Gray, ed., Categories in Computer Science and Logic,
Contemporary Math. **92** (1989), 1–7, Amer. Math. Soc.

Michael Barr,
On categories with effective unions. In F. Bourceux, ed.
Categorical algebra and its applications, Lecture Notes Math.,
**1348**, (1988), 19–35, Springer-Verlag, Berlin, Heidelberg, New
York.

Michael Barr and Michael Makkai
On representations of Grothendieck toposes. Canad. J. Math.,
**39**
(1987), 168–221.

Michael Barr,
Representations of categories. J. Pure Appl. Algebra, **41**
(1986), 113–137.

Michael Barr,
Fuzzy set theory and topos theory. Canad. Math. Bull.,
**26**
(1986), 501–508.

Michael Barr, Colin McLarty, and Charles Wells. Variable set theory Unpublished. This was designed for possible publication in Scientific American, when they had an unfortunately short period of interest in mathematics.

Michael Barr and Charles Wells, Toposes, Triples and Theories. Springer-Verlag, (1984).

Michael Barr,
Abstract Galois Theory II. J. Pure Appl. Algebra **25**
(1982), 227–247.

Michael Barr,
Abstract Galois Theory. J. Pure Appl. Algebra **19** (1980),
21–42.

Michael Barr and R. Diaconescu,
Atomic Toposes. J. Pure Appl. Algebra
**17** (1980), 1–24.

Michael Barr and R. Paré,
Molecular Toposes. J. Pure Appl. Algebra **17**
(1980), 127–152.

Michael Barr with an appendix by P-H Chu,
*-Autonomous Categories. Lecture Notes in Mathematics
**752** (1979), Springer-Verlag.

Michael Barr,
Building closed categories. Cahiers Topologie
Géométrie
Différentielle **19** (1978), 115–129.

Michael Barr,
The theory of theories as a model of syntax acquisition.
Theoretical Linguistics
**5** (1978), 261–274.

Michael Barr,
Duality of vector spaces. Cahiers Topologie Géométrie
Différentielle **18** (1977), 3–14.

Michael Barr,
A closed category of reflexive topological abelian groups.
Cahiers Topologie Géométrie
Différentielle **18** (1977), 221–248.

Michael Barr,
Duality of Banach spaces. Cahiers Topologie Géométrie
Différentielle **17** (1976), 15–32.

Michael Barr,
Closed categories and topological vector spaces. Cahiers
Topologie Géométrie
Différentielle **17** (1976), 223–234.

Michael Barr,
Closed categories and Banach spaces. Cahiers
Topologie Géométrie
Différentielle **17** (1976), 335–342.

Michael Barr,
The existence of injective effacements. Canad. Math. Bull.
**18** (1975), 1–6.

Michael Barr,
Toposes without points. J. Pure Appl. Algebra **5** (1974),
265–280.

Michael Barr,
Coalgebras over a commutative ring. J. Algebra **32** (1974),
600–610.

Michael Barr,
Right exact functors. J. Pure Appl. Algebra
**4** (1974),
1–8.

Michael Barr,
Embedding of categories. Proc.
Amer. Math. Soc. **37** (1973),
42–46.

Michael Barr,
The
point of the empty set. Cahiers Topologie Géométrie
Différentielle **4** (1972), 357–368.

Michael Barr,
Exact Categories.
In: Exact Categories and Categories of
Sheaves, Lecture Notes Math. **236** (1971), 2–121,
Springer-Verlag.

Michael Barr and Max-Albert Knus,
Extensions of derivations. Proc.
Amer. Math. Soc. **28** (1971),
313–314.

Michael Barr, Factorizations, generators and rank. This was an unpublished preprint from 1970 or 1971 that appears here for historical interest only since all the results are now well known. It was cited a few times, but I evidently forgot about during the preparation of Exact categories.

Michael Barr,
Relational algebras.
In: S, Mac Lane, ed. Reports of the
Midwest Category Seminar, IV, Lecture Notes Math. **137**
(1970), 39–55, Springer-Verlag.

Michael Barr,
Coequalizers and free triples. Math. Z. **116** (1970),
307–322.

Michael Barr,
What is the center?
In: S, Mac Lane, ed. Reports of the
Midwest Category Seminar, III, Lecture Notes Math. **106**
(1969), 1–12, Springer-Verlag.

Michael Barr,
Coalgebras in a category of algebras. In
P.J. Hilton, ed. Category Theory, Homology Theory and their
Applications, I.
Lecture Notes Math. **86**
(1969), 1–12, Springer-Verlag.

Michael Barr and Jon Beck,
Homology and standard constructions. Seminar on Triples and
Algebraic Homology Theory, Lecture Notes in Math. Springer (1969)
**80**, 245–334. See also
TAC Reprint 18, 186–248.

Michael Barr, **80** (1968)
Composite cotriples and derived functors. Seminar on Triples and
Algebraic Homology Theory, Lecture Notes in Math. Springer
**80** (1968), 335–356. See also
TAC Reprint 18, 249–266.

Michael Barr,
Cohomology and obstructions: commutative algebras. Seminar on
Triples and Algebraic Homology Theory, Lecture Notes in Math. Springer
**80** (1968), 357–374. See also
TAC Reprint 18, 267–280.

Michael Barr,
Harrison homology, Hochschild homology and triples. J.
Algebra **8** (1968), 314–323.

Michael Barr,
A note on commutative algebra cohomology. Bull. Amer. Math.
Soc. **74** (1968), 310–313.

Michael Barr,
Shukla cohomology and triples.
J. Algebra **5** (1967), 222–231.

Michael Barr and Jon Beck, Acyclic models and triples. Proceedings of the Conference on Categorical Algebra, La Jolla 1965, Springer-Verlag (1966), 336–343.

Michael Barr, Cohomology in tensored categories. Proceedings of the Conference on Categorical Algebra, La Jolla 1965, Springer-Verlag (1966), 344–354.

Michael Barr and G.S. Rinehart,
Cohomology as the derived functor of
derivations. Trans. Amer. Math. Soc. **122** (1966),
416–426.

Michael Barr,
A cohomology theory for commutative algebra II. Proc. Amer. Math.
Soc. **16** (1965), 1385–1391.

Michael Barr,
A cohomology theory for commutative algebra I. Proc. Amer. Math.
Soc. **16** (1965), 1379–1384.

Michael Barr, Cohomology of commutative algebra. Ph.D. Thesis, University of Pennsylvania, 1962. Retyped with a few corections and notes, 2003.

Back to the top Back to the top Michael Barr,
Topological *-autonomous categories, revisited. Tbilisi Math. J.,
**10.3**, 51–64 (2017). This is an updated version of Topological
*-autonomous categories,
Theory Appl. Categories, **16** (2006), 700–708. This paper
corrects
some errors, finishes some badly incomplete proofs, and adds some new
material that answers a question raised by André Joyal.

Michael Barr, John Kennison, and Robert Raphael,
The $*$-autonomous
category of uniform sup semi-lattices. Theory Appl. Categories,
**27** (2012), 222–241.

Michael Barr, John Kennison, and Robert Raphael,
On *-autonomous categories of topological modules.
Theory Appl. Categories, **24** (2010), 278–293.

Michael Barr, John Kennison, and Robert Raphael,
Isbell duality for modules. Theory Appl. Categories,
**22** (2009), 401–419.

Michael Barr, John Kennison, and Robert Raphael,
Isbell duality. Theory Appl. Categories,
**20** (2008), 504–542.

Michael Barr,
Topological *-autonomous categories. Theory Appl. Categories,
**16** (2006), 700–708.

Michael Barr,
The
Chu construction: history of an idea. Proceedings of a conference
on Chu categories, UC Santa-Barbara, 2002. Theory Appl. Categories,
**17**, (2006), 10–16.

Michael Barr, On duality of topological abelian groups. Unpublished note.

Michael Barr,
A duality on simplicial complexes. Georgian Math. J., **9**
(2002), 601–605.

Michael Barr and Heinrich Kleisli,
On Mackey topologies in topological abelian
groups. Theory Appl. Categories, **8** (2001),
54–62.

Michael Barr,
On *-autonomous categories of topological vector spaces. Cahiers
Topologie Géométrie Différentielle Catégorique,
**41** (2000), 243–254.

Michael Barr,
*-Autonomous categories: once more around the track. Theory Appl.
Categories, **6** (1999), 5–24.

Michael Barr and Heinrich Kleisli,
Topological balls. Cahiers Topologie Géométrie
Différentielle Catégorique, **40** (1999),
3–20.

Michael Barr,
The separated extensional Chu category. Theory Appl. Categories,
**4** (1998), 127–137.

Michael Barr, Notes on Linear logic and *-autonomous categories and on Sketches. Technical report of the Electrotechnical Laboratory (computer language section), Tsukuba, Japan, 1997, 28 pages.

Michael Barr,
Separability of tensor in Chu categories of vector spaces.
Math. Structures Comp. Sci., **6**
(1996), 213–217.

Michael Barr,
The Chu construction. Theory Appl. Categories, **2** (1996),
17–35.

Michael Barr,
*-Autonomous categories, revisited. J. Pure Applied Algebra,
**111** (1996), 1–20.

Michael Barr,
Non-symmetric *-autonomous categories. Theoretical Computer
Science, **139** (1995), 115–130.

Michael Barr,
Algebraically compact functors. J. Pure Appl. Algebra, **82**
(1992), 211–232.

Michael Barr,
*-Autonomous categories and linear logic. Math. Structures Comp.
Sci., **1** (1991), 159–178.

Michael Barr with an appendix by P-H Chu,
*-Autonomous Categories. Lecture Notes in Mathematics
**752** (1979), Springer-Verlag.

Michael Barr,
Building closed categories. Cahiers Topologie
Géométrie
Différentielle **19** (1978), 115–129.

Michael Barr,
Duality of vector spaces. Cahiers Topologie Géométrie
Différentielle **18** (1977), 3–14.

Michael Barr,
A closed category of reflexive topological abelian groups.
Cahiers Topologie Géométrie
Différentielle **18** (1977), 221–248.

Michael Barr,
Duality of Banach spaces. Cahiers Topologie Géométrie
Différentielle **17** (1976), 15–32.

Michael Barr,
Closed categories and topological vector spaces. Cahiers
Topologie Géométrie
Différentielle **17** (1976), 223–234.

Michael Barr,
Closed categories and Banach spaces. Cahiers
Topologie Géométrie
Différentielle **17** (1976), 335–342.

Michael Barr, Injectivity of the circle in locally compact abelian groups Unpublished. This gives all the details of the title statement, although it can be gleaned from the literature. (2022)

Michael Barr,
Algebraic cohomology: the early days. Fields Institute
Communications, **42** (2004), 1–26.

Michael Barr,
Absolute cohomology. Theory Appl. Categories, **14**, (2005),
53–59.

Michael Barr Acyclic Models. Amer. Math. Soc. (2002, rev. 2017), xii + 238 pages.

Michael Barr,
Acyclic models. Canadian J. Math.,
**48** (1996), 258–273.

Michael Barr,
Cartan-Eilenberg cohomology and triples. J. Pure Applied Algebra,
**112** (1996), 219–238.

Michael Barr,
Oriented singular homology. Theory Appl. Categories, **1**
(1995), 1–9.

Michael Barr and Max-Albert Knus,
Extensions of derivations. Proc.
Amer. Math. Soc. **28** (1971),
313–314.

Michael Barr,
Coequalizers and free triples. Math. Z. **116** (1970),
307–322.

Michael Barr and Jon Beck,
Homology and standard constructions. Seminar on Triples and
Algebraic Homology Theory, Lecture Notes in Math. Springer (1969)
**80**, 245–334. See also
TAC Reprint 18, 186–248.

Michael Barr, **80** (1968)
Composite cotriples and derived functors. Seminar on Triples and
Algebraic Homology Theory, Lecture Notes in Math. Springer
**80** (1968), 335–356. See also
TAC Reprint 18, 249–266.

Michael Barr,
Cohomology and obstructions: commutative algebras. Seminar on
Triples and Algebraic Homology Theory, Lecture Notes in Math. Springer
**80** (1968), 357–374. See also
TAC Reprint 18, 267–280.

Michael Barr,
Harrison homology, Hochschild homology and triples. J.
Algebra **8** (1968), 314–323.

Michael Barr,
A note on commutative algebra cohomology. Bull. Amer. Math.
Soc. **74** (1968), 310–313.

Michael Barr,
Shukla cohomology and triples.
J. Algebra **5** (1967), 222–231.

Michael Barr and Jon Beck, Acyclic models and triples. Proceedings of the Conference on Categorical Algebra, La Jolla 1965, Springer-Verlag (1966), 336–343.

Michael Barr, Cohomology in tensored categories. Proceedings of the Conference on Categorical Algebra, La Jolla 1965, Springer-Verlag (1966), 344–354.

Michael Barr and G.S. Rinehart,
Cohomology as the derived functor of
derivations. Trans. Amer. Math. Soc. **122** (1966),
416–426.

Michael Barr,
A cohomology theory for commutative algebra II. Proc. Amer. Math.
Soc. **16** (1965), 1385–1391.

Michael Barr,
A cohomology theory for commutative algebra I. Proc. Amer. Math.
Soc. **16** (1965), 1379–1384.

Michael Barr, Cohomology of commutative algebra I. Ph.D. Thesis, University of Pennsylvania, 1962. Retyped with a few corections and notes, 2003.

Back to the top
Michael Barr and Michael Makkai
On representations of Grothendieck toposes. Canad. J. Math.,
**39**
(1987), 168–221.

Michael Barr,
Fuzzy set theory and topos theory. Canad. Math. Bull.,
**26**
(1986), 501–508.

Michael Barr and Charles Wells, Toposes, Triples and Theories. Springer-Verlag, (1984).

Michael Barr and R. Diaconescu,
Atomic Toposes. J. Pure Appl. Algebra
**17** (1980), 1–24.

Michael Barr and R. Paré,
Molecular Toposes. J. Pure Appl. Algebra **17**
(1980), 127–152.

Michael Barr,
Toposes without points. J. Pure Appl. Algebra **5** (1974),
265–280.

Joachim Lambek, Michael Barr, John Kennison, and Robert Raphael,
Injective
hulls of partially ordered monoids. Theory Appl. Categories,
**26** (2012), 338–348.

Michael Barr, John Kennison, and Robert Raphael,
Countable meets in coherent spaces with applications to the
cyclic spectrum.
Theory Appl. Categories, **25** (2011), 508–232.

Michael Barr, John Kennison, and Robert Raphael,
Flows: cocyclic and almost cocyclic.
Theory Appl. Categories, **25** (2010), 490–507.

Michael Barr, John Kennison, and Robert Raphael,
Searching for more absolute CR-epic spaces. Theory Appl. Categories,
**22** (2009), 54–76.

Michael Barr,
On subpregroups of the Lambek pregroup. Theory Appl.
Categories, **12**, (2004), 262–269.

Michael Barr,
On subpregroups of the Lambek pregroup. Abstract: To appear in
Lambekfestschrift. Full paper: Theory Appl. Categories, **12**
(2004), 262–269.

Michael Barr,
HSP subcategories of Eilenberg-Moore algebras. Theory Appl.
Categories, **10** (2002), 461–468.

Michael Barr and Charles Wells Category Theory for Computing Science. Reprinted by the Centre de Recherche Maththématique (Revised edition, 1999).

Michael Barr and M.C. Pedicchio,
Top^{op} is a quasi-variety. Cahiers
Topologie Géométrie Différentielle Catégorique, **36**
(1995), 3–11.

Michael Barr,
Functorial semantics and HSP type theorems. Algebra Universalis,
**31** (1994), 223–241.

Michael Barr,
Terminal coalgebras for endofunctors on sets. Theoretical Comp.
Sci., **114** (1993), 299–315.

Michael Barr,
HSP type theorems in the category of posets. Proc. 7th
International Conf. Mathematical Foundation of Programming Language
Semantics, Lecture Notes in Computer Science, **598** (1992),
221–234.

Michael Barr,
Fixed points in cartesian closed categories. Theoretical Comp.
Sci., **70** (1990), 65–72.

Michael Barr,
Accessible categories and models of linear logic. J. Pure Appl.
Algebra, **69** (1990), 219–232.

Michael Barr,
Models of Horn theories.
In J. W. Gray, ed., Categories in Computer Science and Logic,
Contemporary Math. **92** (1989), 1–7, Amer. Math. Soc.

Michael Barr,
On categories with effective unions. In F. Bourceux, ed.
Categorical algebra and its applications, Lecture Notes Math.,
**1348**, (1988), 19–35, Springer-Verlag, Berlin, Heidelberg, New
York.

Michael Barr,
Representations of categories. J. Pure Appl. Algebra, **41**
(1986), 113–137.

Michael Barr, Toposes, Triples and Theories. Springer-Verlag, (1984).

Michael Barr,
Abstract Galois Theory II. J. Pure Appl. Algebra **25**
(1982), 227–247.

Michael Barr,
Abstract Galois Theory. J. Pure Appl. Algebra **19** (1980),
21–42.

Michael Barr,
The existence of injective effacements. Canad. Math. Bull.
**18** (1975), 1–6.

Michael Barr,
Coalgebras over a commutative ring. J. Algebra **32** (1974),
600–610.

Michael Barr,
Right Exact Functors. J. Pure Appl. Algebra
**4** (1974),
1–8.

Michael Barr,
Embedding of categories. Proc.
Amer. Math. Soc. **37** (1973),
42–46.

Michael Barr,
The
point of the empty set. Cahiers Topologie Géométrie
Différentielle **4** (1972), 357–368.

Michael Barr, Factorizations, generators and rank. This was an unpublished preprint from 1970 or 1971 that appears here for historical interest only since all the results are now well known. It was cited a few times, but I evidently forgot about during the preparation of Exact categories.

Back to the top Michael Barr, John Kennison, and Robert Raphael,
Contractible simplicial objects
Comm. Math. Univ. Carol. **60** (2019), 473–495.

Michael Barr, John Kennison, and Robert Raphael,
Local extension of maps. New York J. Math.
**15** (2009), 254–264.

Michael Barr, John Kennison, and Robert Raphael,
On productively Lindelöf spaces. Scient. Math. Japon.
**65** (2007), 23–36.

Michael Barr, John Kennison, and Robert Raphael,
Searching for absolute CR-epic spaces. Canadian J. Math. **59**
(2007), 465–487.

Michael Barr, Robert Raphael, and R. Grant Wood,
On CR-epic embeddings and absolute
CR-epic spaces. Can. J. Math. **57** (2005),
1121–1138.

Michael Barr, Walter Burgess, and Robert Raphael,
Ring epimorphisms and *C(X)*.
Theory Appl. Categories, **11** (2003), 283–308.

Michael Barr, Rational Erdos numbers. An unpublished bit of amusement, written in 2003, suggesting a modification of the Erdos number to take account of multiple collaborations.

Michael Barr,
Note on a theorem of Putnam's. Theory Appl. Categories, **3**
(1997), 45–49.

Michael Barr,
Fuzzy models of linear logic. Math. Structures Comp. Sci., **6**
(1996), 301–312.

Michael Barr,
The theory of theories as a model of syntax acquisition.
Theoretical Linguistics
**5** (1978), 261–274.

Michael Barr, Functional set theory. Unpublished. (Chandler Davis, editor of the Intelligencer, commissioned this paper, after hearing me mouth off about the paper referred to. He ``virtually'' (his word) guaranteed publication, although he could not actually guarantee it, which I understood. Not only didn't he ever publish it, he never had the courtesy to tell me that, but let the passage of time, now well over a decade, carry out this task.)

Michael Barr, Colin McLarty, and Charles Wells. Variable set theory Unpublished. This was designed for possible publication in Scientific American, when they had an unfortunately short period of interest in mathematics.

Back to the topJ. Lambek, Programs, Grammars, Arguments. Unpublished notes. (2007).

N. J. Fine, L. Gillman and J. Lambek, Rings of Quotients of Rings of Continuous Functions. Originally published by McGill University, 1965.

Alexandre Grothendieck, Some aspects of homological algebra. Translation by Marcia L. Barr and Michael Barr of, Sur quelques points d'algèbre homologique.

Rob van Glabbeek,
Untitled manuscript This is an unpublished proof that when an open
domain in R^{n} is embedded into R^{n} by a
diffeomorphism of class
at least C^{2}, then at each point the images of sufficiently
small balls are convex.

diagxy.tex Macros for making diagrams.

diaxydoc.tex Source for diagxydoc.pdf.

diaxydoc.pdf Tutorial and documentation for diagxy.

timestamp Macro for putting time and datestamp in a TeX file.

June 30, 2015