Books written or edited by Michael F. Singer
    
      
      
      -  Integration in Finite Terms: Fundamental Sources, C.G.
        Raab, M.F. Singer (editors),  Texts & Monographs in
          Symbolic Computation, Springer Cham, 2022,
        https://link.springer.com/book/10.1007/978-3-030-98767-1 
 
 
- Galois Theories of Linear Difference Equations: An
          Introduction, C. Hardouin, J. Sauloy, M.F. Singer
        (editors), Mathematical Surveys and Monographs,  Volume
211,
American
        Mathematical Society, 2016
        
        
 
 
-  Differential Galois Theory, M. van der Put and M. F.
        Singer, (.ps file) (manuscript,
        433 pages), 2001.  Revised edition
          July 2002 Published as  Galois Theory of Linear
          Differential Equations  Grundlehren der
          mathematischen Wissenschaften, Volume 328, Springer, 
        2003. 
 
 
-   Effective Methods in Algebraic Geometry,  M.F.
        Singer (editor). Selected papers from the conference 
          Methodes Effectives en Geometrie Algebriques (MEGA2000),
         Journal of Pure and Applied Algebra, Volume 164,
        Issues 1-2, October 2001  
 
 
- Galois Theory of Difference Equations, M. van der Put
        and M. F. Singer, V. 1666 in  Lecture Notes in Mathematics,
          Springer-Verlag, 1997. 
          Errata (.ps file), 
          Errors in proof of Theorem 3.1 of Chapter 3 
 
 
-  Differential Equations and Computer Algebra, M.F.
        Singer, editor, Academic Press, 1991. (This is a collection of
        papers from the Computer Algebra and Differential Equations
        Conference held in Ithaca in May 1990) 
 
 
    Papers by Michael F. Singer
    
    
       Preprints
        
       
      
      - On Deciding Transcendence of Power
          Series (with A. Bostan, B. Salvy). Submitted 2025
 
          - Integrals of Solutions of
              Linear Differential Equations . This is a manuscript
            containing an explication of some results from Daniel
            Bertrand's paper ``Extensions de D-modules et groupes de
            Galois différentielles"; in particular, a result giving
            necessary and sufficient condtions for the integral of a
            solution of a homogeneous linear differential equation to be
            algebraically dependent on the solutions of this equation.
            2025
 
              - Comments on 
                    Ueber algebraisch integrirbare lineare
                    Differntialgleichungen by F.G. Frobenius In
                this 1875 paper, Frobenius proves (among other things)
                that if all solution of an irreducble homogneous linear
                differential equation of order greater than 2 can be
                expressed as a rational function of one of them, then
                all solutions of the equation are algebraic.I present
                the proof in English and replace Frobenius's use of the
                monodromy group with the differential Galois group.
                2023.
 
                  - Mahler equations
                      and rationality (with R. Schaefke), Preprint,
                    2016. This contains another proof of a result of
                    Adamczewski and Bell concerning Mahler equations: A
                    formal power series satisfying a p− and a q−Mahler
                    equation over C(x) with multiplicatively independent
                    positive integers p and q is a rational function.
                    The proof presented here is self-contained and is
                    essentially a compilation of proofs contained in
                    the  preprint "Consistent systems of linear
                    differential and difference equations".
                  - Asymptotic Behavior of
                      Solutions of Differential Equations and Hardy
                      Fields: Preliminary Report. This is an
                    unpublished manuscript written in 1975.
              
              
                
                 2024
                
                - Telescopers for
                    differential forms with one parameter (with S. Chen,
                    R. Feng, Z. Li, S.M. Watt) Selecta
                    Mathematica 30:34,2024.
                    https://doi.org/10.1007/s00029-024-00926-6 
                    
                     2022
                    
                    - Comments on
                        Rosenlicht's Integration in Finite Terms
                      In:  Integration in Finite Terms:
                        Fundamental Sources, C.G.Raab, M.F. Singer
                      (editors),  Texts & Monographs in Symbolic
                        Computation, Springer Cham, 2022,pp. 11-30.
                    -  MSRI Addresses
                        the Challenge (with H. Barcelo) In: 
                        Count Me In: Community and Belonging in
                        Mathematics, D. Dumbaugh, D. Haunsperger
                      (eds.), Classroom Resource Materials, Vol. 68,
                      American Mathematical Society, 2022, pp.231-240.
                      Also appears in the Notices of the American
                        Mathematical Society, June/July 2022, pp.
                      955-961.
 
                    - On the
                        algebraic dependence of holonomic functions
                        (with J. Roques), Annales Henri
                        Lebesgue.,Vol. 5, pp.141--177, 2022.
                    -  Sparse
                        Interpolation in Terms of Multivariate Chebyshev
                        Polynomials (with E. Hubert), Foundations
                        of Computational Mathematics, vol.22,
                      pp.1801-1862,2022.  
                    
                    2021
                    
                    -  Separability
                        Problems in Creative Telescoping (with Shashi
                        Chen, Ruyong Feng, and Pingchuan Ma), Proceedings
                        of ISSAC 2021, (M. Mezzarobba, ed.), 83-90,
                      2021.
                    - On Differentially
                        Algebraic Generating Series for Walks in the
                        Quarter Plane (with C.Hardouin), Maple Worksheets,
                      2021, Selecta Mathematica New Ser. 27, 89
                        (2021).
                        https://doi.org/10.1007/s00029-021-00703-9
                      - On the kernel
                          curves associated with walks in the quarter
                          plane (with T. Dreyfus, C. Hardouin, J.
                          Roques), Discriminant calculations: maple code, 
                        pdf file,
                        In: Bostan A., Raschel K. (eds) Transcendence in
                        Algebra, Combinatorics, Geometry and Number
                        Theory. TRANS 2019. Springer Proceedings in
                        Mathematics & Statistics, vol 373. Springer,
                        Cham.
                        https://doi.org/10.1007/978-3-030-84304-5_3,
                        pp.61-89
 
                      
                      2020
                       
                      - Some
                          Structural Results on D^n-finite Functions
                          (with V. Pillwein and A. Jimenez-Pastor),
                        Advances in Applied Mathematics, Vol.
                        117, June 2020
 
                      - Walks on
                          the Quarter Plane, Genus Zero Case (with T.
                          Dreyfus, C. Hardouin, J. Roques), Journal
                          of Combinatorial Theory A, Vol. 174,
                        August 2020.
 
                      
                      2019
                      
                      - Consistent
                          systems of linear differential and difference
                          equations (with R. Schaefke), Journal
                          of the European Mathematical Society, Vol.21,
                        Issue 9, 2751-2792, 2019
 
                      
                      2018
                      
                      -  On the
                          Nature of the Generating Series of Walks in
                          the Quarter Plane (with T. Dreyfus, C.
                          Hardouin, J. Roques), Inventiones
                          mathematicae, Vol. 213, Issue 1,
                        pp.139-204, 2018. 
                      
                      2017
                      
                      - Galois groups
                          for integrable and projectively integrable
                          linear differential equations (with C.
                          Arreche), Journal of Algebra, 
                        Vol. 480, 423–449, 15 June 2017,
                        dx.doi.org/10.1016/j.jalgebra.2017.02.032 
 
                      
                      2016
                      
                      - Algebraic and
                          Algorithmic Aspects of Linear Difference
                          Equations, Galois Theories of Linear
                          Difference Equations: An Introduction (C.
                        Hardouin, J. Sauloy, M. F. Singer), Mathematical
                        Surveys and Monographs, Volume 211, American
                        Mathematical Society, 2016, pp.12-53.
                      - Desingularization
                          of Ore Operators (with S. Chen and M. Kauers), 
                        Journal of Symbolic Computation, Vol.
                        74, 617-626, May-June 2016. 
                          
                        
                      
                      2015
                      
                      - Reductive
                          linear differential algebraic groups and the
                          Galois groups of parameterized linear
                          differential equations (with A. Minchenko and
                          A. Ovchinnikov),  International
                          Mathematics Research Notices,  Vol.
                        215, Issue 7, 1733-1793, 2015.
                       2014 
                      
                      - Unipotent
                          differential algebraic groups as parameterized
                          differential Galois groups (with A. Minchenko
                          and A. Ovchinnikov), Journal of the
                          Institute of Mathematics of Jussieu,
                        volume 13, issue 04, 671-700.
                      -  Parallel
                          Telescoping and Parameterized Picard–Vessiot
                          Theory (with S. Chen, R. Feng and Z. Li),
                        Proceedings of ISSAC 2014, pp. 99–106,
                        ACM Press, 2014. 
                      - On the
                          Summability of Bivariate Rational Functions
                          (with S. Chen), Journal of Algebra,
                        409, (2014), 320-343.
                       2013 
                      
                      - Desingularization
                          Explains Order-Degree Curves for Ore Operators
                          (with S. Chen, M. Jaroschek and M. Kauers), 
                        Procedings of ISSAC 2013, ( M. Kauers, ed.),
                        157-164, 2013.
                      - Projective
                          Isomonodromy and Galois Groups (with C.
                          Mitschi), Proceedings of the American
                          Mathematical Society, 141 (2013),
                        no. 2, 605-617.
                      
                      - Linear
                          Algebraic Groups as Parameterized
                          Picard-Vessiot Galois Groups, Journal of
                          Algebra, 373, (2013), 151--161, Old version,
                        2011.
                       2012 
                      
                      - Monodromy
                          Groups of Parameterized Linear Differential
                          Equations with Regular Singularities (with C.
                          Mitschi), Bull. London Math. Soc., 44(5), 2012,
                        913-930. 
                      
                      - Residues and
                          Telescopers for Bivariate Rational Functions
                          (with S. Chen),  Advances in
                          Applied Mathematics, 49 (2012)
                        111–133.   
 
                      - Telescopers
                          for Raltional and Algebraic Functions via
                          Residues (with S. Chen and M. Kauers), 
                        Procedings of
                          ISSAC 2012, (J. van der Hoeven and M.
                        van Hoeij, eds.), 130-137, 2012.
                       2011 
                      
                      - A
                          Jordan-Hoelder Thoerem for Differentail
                          Algebraic Groups (with P. Cassidy) Journal
                          of Algebra, 328, 2011, 190–217.
                       2010 
                      
                      - Liouvillian
                          solutions of difference-differential equations
                          (with R. Feng, M. Wu)  Journal of
                          Symbolic Computation, 45, 2010,
                        287-305.
 
                      - An
                          algorithm to compute liouvillian solutions of
                          prime order difference-differential equations
                          (with R. Feng, M. Wu) Journal of
                          Symbolic Computation, 45, 2010,
                        306-323.
 
                      2009
                      
                      - Introduction
                          to the Galois Theory of Linear Differential
                          Equations Algebraic Theory of Differential
                          Equations, M.A.H. MacCallum and A.V.
                        Mikhalov, eds., London Mathematical Society
                        Lecture Note Series (no. 357), Cambridge
                        University Press, 2009, 1-82.
 
 
2008
                      
                      - Differential
                          Galois Theory of Linear Difference Equations
                          (with C. Hardouin) Mathematische
                          Annalen, 342(2) 2008, 333-377 Erratum Some of
                        the calculations referred to in this paper are
                        contained in a Maple Worksheet entitled Differential
                          independence of a class of q-hypergeometric
                          difference equations (a pdf version of
                        this may be found here).
 
 
- On
                          the Definitions of Difference Galois Groups
                          (with Z. Chatzidakis, C. Hardouin) Model Theory with
                          applications to algebra and analysis, I and II,
                        (Z. Chatzidakis, H.D. Macpherson, A. Pillay,
                        A.J. Wilkie editors), Cambridge University
                        Press, Cambridge.(2008), 73-109. 
 
 
                      2007 
                      
                      - Model
                          Theory of Differential Fields: From Commuting
                          to Noncommuting Derivations  Proceedings of the
                          AMS., 135  (2007), 1929-1934.
                        
 
 
                      2006 
                      
                      - Galois
                          Theory of Parameterized Differential Equations
                          and Linear Differential Algebraic Groups (with
                          P.J. Cassidy)  Differential
                          Equations and Quantum Groups (IRMA
                        Lectures in Mathematics and Theoretical Physics
                        Vol. 9), ed. D. Bertrand, B. Enriquez, C.
                        Mitschi, C. Sabbah, R. Schaefke, EMS Publishing
                        house  pp. 113- 157 (2006).
                      - A Recursive
                          Method for Determining the One-Dimensional
                          Submodules of Laurent-Ore Modules (with Z. Li,
                          M. Wu, D. Zheng). 2006.  Proceedings of
                          ISSAC 2006, pp. 200-208.
 
                      
                      2005 
                      
                      - On
                          the Constructive Inverse Problem in
                          Differential Galois Theory, (with W. Cook and
                          C. Mitschi) (.pdf file) ,  Comm. in
                          Algebra ,  33/10, 2005, pp.
                        3639-3665. An older version is available  here. Related
                        software is available  here. 
 
 
 2002
 
 
- Solvable-by-Finite
                          Groups as Differential Galois Groups (with C.
                          Mitschi). Ann. Fac. Sci. Toulouse
                          Math. (6)  11/3  (2002), 403-423
                        
 
 
- Linear Differential
                          Operators for Polynomial Equations (with O.
                          Cormier, B.M. Trager and F. Ulmer) (.pdf file)
                         Journal of Symbolic Computation,
                         34 , 2002, pp.355-398. 
 
 2000
 
 
- Computing the
                          Galois Group of a Polynomial Using Linear
                          Differential Equations (with O. Cormier, F.
                          Ulmer) (.ps file) Proceedings of
                          ISSAC 2000., 78-85 
 
 1999
 
 
- Computing
                          Galois Groups of Completely Reducible
                          Differential Equations (with E. Compoint) (.ps
                          file). Journal of Symbolic
                          Computation,  28/4-5, 1999,
                        473-494. Also available as a  .dvi file 
 
 
- Calculating
                          the Galois group of L_1(L_2(y))=0, L_1, L_2
                          Completely Reducible Operators (with P.
                          Berman) (.pdf file) and Abstract. 
                          Journal of Pure and Applied Algebra, 
                          139/1-3, 1999, 3-24. 
 
 
- Solving Difference
                          Equations in Finite Terms (with P. Hendriks) .
                         Journal of Symbolic Computation, 27/3,
                        1999, 239-259. 
 
 
-  Direct and
                          Inverse Problems in Differential Galois Theory
                          (.ps file).  Selected Works of Ellis
                          Kolchin with Commentary , Bass, Buium,
                        Cassidy, eds., American Mathematical Society,
                        1999, 527-554. Also available as a  .dvi file 
 
 1998
 
 
- Relations
                          Lineaires entre Solutions d'une Equation
                          Differentielle (with E. Compoint) (.ps file).
                        Annales des Fac. des Science de Toulouse,
                        Vol. VII, No. 4, 1998, 659-670. Also available
                        as a  .dvi file 
                        
 
 1997
 
 
- Linear Differential
                          Equations and Products of Linear Forms (with
                          F. Ulmer) (.ps file).  Journal of
                          Pure and Applied Algebra, 117-118,
                        1997, 549-563. Also available as a  .dvi file  
 
 1996
 
 
-  Testing Reducibility of
                          Linear Differential Operators: A Group
                          Theoretic Perspective ,  Applicable
                          Algebra in Engineering, Communication and
                          Computing, 7(2), 1996, 77-104. 
                      -   On Ramis's
                          Solution of the Local Inverse Problem of
                          Differential Galois Theory (with C. Mitschi),  Journal of
                          Pure and Applied Algebra, 110,
                        1996, 185-194. 
 
 
- Connected
                          Linear Groups as Differential Galois Groups
                          (with C. Mitschi) (.ps file), 
                          Journal of Algebra,  184, 1996,
                        333-361. Also available as a  .dvi file  
 
 
-  The Inverse
                          Problem in Differential Galois Theory (with C.
                          Mitschi) (.ps file) , in  The Stokes
                          Phenomenon and Hilbert's 16th Problem,
                        B.l.J. Braaksma, et. al., eds., World
                        Scientific, Singapore, 1996, 185-196. Also
                        available as a  .dvi
                          file  
 
 
-   On the
                          Infinitesimal Geometry of Integrable Systems
                          (with A. Baider, R. Churchill, D. Rod) (.ps
                          file) , in  Mechanics Day,
                        Shadwich et. al., eds, Fields Institute
                        Communications,  7 , American
                        Mathematical Society, 1996, 5-56. Also available
                        as a  .dvi file
                         
 
 1995
 
 
-   Necessary
                          Conditions for Liouvillian Solutions of (Third
                          Order) Linear Differential Equations (with F.
                          Ulmer) (.ps file),  Applied Algebra
                          in Engineering, Communication and Computing,
                         6(1), 1995, 1 - 22. Also available as a
                         .dvi file ;
                        an extended abstract of this paper appeared in
                        the  Proceedings of the International
                          Symposium on Symbolic and Algebraic
                          Computation (ISSAC `92), ACM Press. 
 
 
-  Group Theoretic
                          Obstructions to Integrability (with R.
                          Churchill, D. Rod) (.ps file), 
                          Ergodic Theory and Dynamical Systems} ,
                         15, 1995, 15 -48 . Also available as a  .dvi file  
 
 
-   On Computing
                          Algebraic Functions using Logarithms and
                          Exponentials (with D. Grigoriev, A. Yao) (.ps
                          file) , SIAM J. Comp.,  24(2),
                        1995, 242 - 246. Also available as a  .dvi file  
 
 1994
 
 
-  
                          Computational Complexity of Sparse Rational
                          Function Interpolation (with D. Yu. Grigor'ev,
                          M. Karpinski) (.ps file),  SIAM J. of
                          Computing, 23, 1994, 1- 11. Also
                        available as a 
                          .dvi file  
 
 1993
 
 
-  Moduli of Linear
                          Differential Equations on the Rieman Sphere
                          with Fixed Galois Groups ,  Pacific
                          Journal of Mathematics, 106(2),
                        1993, 343-395. 
 
 
-  Computational Complexity of Sparse Real
                        Algebraic Function Interpolation (with D. Yu.
                        Grigor'ev, M. Karpinski), in the 
                          Proceedings of the Conference on Effective
                          Methods in Algebraic Geometry (MEGA '92),
                        April 1992, Progress in Math., Birkhaeuser, 109
                        1993, 91--104. 
 
 
-   Galois
                          Groups of Second and Third Order Linear
                          Differential Equations (with F. Ulmer) ,
                         Journal of Symbolic Computation, 
                          16, July 1993, 9 - 36. 
 
 
-  Liouvillian
                          and Algebraic Solutions of Second and Third
                          Order Linear Differential Equations, (with F.
                          Ulmer),  Journal of Symbolic
                          Computation,  16, July 1993, 37 -
                        74. Also available as a  .dvi file 
                        
 
 
-  On a Third Order
                          Differential Equation Whose Differential
                          Galois Group is a Simple Group with 168
                          Elements (with F. Ulmer), 
                          Proceedings of the 10th International
                          Symposium on Applied Algebra, Algebraic
                          Algorithms and Error Correcting Codes, Puerto
                          Rico, May 1993, in Lecture Notes in
                        Computer Science,  519. 
 
 
- On Integer Zeros of Exponential Polynomials
                        (with C. W. Henson, L. A. Rubel, L. van den
                        Dries),  Complex Variables Theory and
                          Applications,  23(3-4), 1993,
                        201-211. 
 
 1992
 
 
-  Liouvillian
                          First Integrals of Differential Equations,
                         Transactions of the AMS, 333(2),
                        October 1992, 673-688. 
 
 1991
 
 
-  Solving
                          Ordinary Differential Equations in Terms of
                          Series with Real Exponents (with D. Yu.
                          Grigor'ev),  Transactions of the
                          A.M.S.,  327(1), 1991, 329-351, .
                        
 
 
-  Liouvillian
                          Solutions of Linear Differential Equations
                          with Liouvillian Coefficients,  J. of
                          Symbolic Computation,  11(3),
                        1991, 251-274. 
 
 
- The Interpolation
                          Problem for k-Sparse Sums of Eigenfunctions of
                          Operators (with D. Yu. Grigor'ev, M.
                          Karpinski),  Advances in Applied
                          Mathematics, 12, 1991, 76-81 
 
 
- Size efficient parallel algebraic circuits for
                        partial derivatives (with E. Kaltofen), in 
                          IV International Conference on Computer
                          Algebra in Physical Research, D. V.
                        Shirkov, V. A. Rostovtsev, and V. P. Gerdt, ed.,
                        World Scientific Publ., Singapore, 1991, 133-145
                        . 
 
 1990
 
 
- Fast
                          Parallel Algorithms for Sparse Multivariate
                          Polynomial Interpolation over Finite Fields
                          (with D. Yu. Grigor'ev and M. Karpinski),
                         SIAM J. of Computation,  19(6),
                        December 1990, 1059 - 1063. 
 
 
-  Formal Solutions
                          of Differential Equations,  J. of
                          Symbolic Computation,  10, 1990,
                        59-94. 
 
 
-  Interpolation
                          of Sparse Rational Functions without Knowing
                          the Bounds on Exponents (with D. Yu.
                          Grigor'ev, M. Karpinski), 
                          Proceedings of the 1990 IEEE Foundations of
                          Computer Science Conference, IEEE
                        Computer Society Press, 1990, 840 - 847. 
 
 1989
 
 
-  Algebraic
                          Properties of the Ring of General Exponential
                          Polynomials (with C. W. Henson, L. Rubel),
                          Complex Variables Theory and Applications,
                         13, 1989, 1-20. 
 
 
-  An Outline of
                          Differential Galois Theory, in 
                          Computer Algebra and Differential Equations,
                        E. Tournier, ed., Academic Press, 1989, 3-58 
 
 1988
 
 
-  Algebraic
                          Relations Among Solutions of Linear
                          Differential Equations: Fano's Theorem, 
                          Am. J. of Math.,  110, 1988,
                        115-143. 
 
 
-  Autonomous
                          Functions (with L. Rubel),  Journal
                          of Differential Equations,  75(2),
                        1988 
 
 1986
 
 
-  Algebraic
                          Relations Among Solutions of Linear
                          Differential Equations,  Transactions
                          of the American Mathematics Society , 295(2),
                        1986,753-763. 
 
 
- Elementary
                          and Liouvillian Solutions of Linear
                          Differential Equations (with J. Davenport),
                         Journal of Symbolic Computation, 
                          2(3), 1986, 237-260. 
 
 1985
 
 
-  An
                          Extension of Liouville's Theorem on
                          Integration in Finite Terms (with B. D.
                          Saunders and B. F. Caviness), SIAM
                          Journal of Computing,  14, 1985,
                        966-990 . 
 
 
-  Solving
                          Homogeneous Linear Differential Equations in
                          Terms of Second Order Linear Differential
                          Equations,  Am. J. of Math., 
                          107, 1985, 663-696. 
 
 
-  Aplications
                          of Linear Groups to Differential Equations
                          (with M. Tretkoff),  American Journal
                          of Mathematics,  107, 1985,
                        1093-1109. 
 
 
-  A
                          Classification of Differential Equations of
                          Fuchsian Class (with M. Tretkoff), 
                          American Journal of Mathematics, 107,
                        1985, 1111-1121. 
 
 
-  
 
A Class
                        of Vectorfields on S2 that are Topologically
                        Equivalent to Polynomial Vectorfields (with S.
                        Schecter),  Journal of Differential
                        Equations,  57 (3), 1985, 406-435.
                      
                      -  A Differentially Algebraic Elimination
                        Theorem with Applications to Analog
                        Computatbility in the Calculus of Variations
                        (with L. Rubel),  Proceedings of the
                          American Mathematical Society,  94(4),
                        1985, 635-658. 
 
 1983
 
 
-  Elementary
                          First Integrals of Differential Equations
                          (with M. Prelle),,  Transactions of
                          the American Mathematical Society ,
                        279(1), September 1983, 215-229. 
 
 1981
 
 
- Liouvillian
                          Solutions of nth Order Homogeneous Linear
                          Differential Equations,  Am. J. Math.,
                         103(4), 1981, 661-682. 
 
 1980
 
 
- Remarks on
                          Analytic Continuation (with F. Haimo and
                        M. Tretkoff),  Bulletin of the London
                          Mathematical Society, 12, 1980,
                        9-12. 
 
 
-  Planar
                          Polynomial Foliations (with S. Schecter),
                         Proceedings of the American Mathematical
                          Society,  79 (4), August 1980,
                        649-656. Addendum
                        . 
 
 
-  Singular Points of Planar Vector Fields (with
                        S. Schecter), in  Globay Theory of Dynamic
                          Systems , Lecture Notes in Mathematics,
                         819, Springer-Verlag, 393-410. 
 
 
-  Separatrices at Singular Points of Planar
                        Vector Fields (with S. Schecter),  Acta
                          Mathematica, 145, 1980, 47-78 ;
                        correction in  151, 1983, 297-298. 
 
 1979
 
 
- A Class of
                          Differential Fields with Minimal Differential
                          Closures,  Proceedings of the
                          American Mathematical Society, 69(2),
                        1979, 319-322. 
 
 
- The
                          Model Theory of Ordered Differential Fields,
                         The Journal of Symbolic Logic,  43(1),
                        1979, 82-91. 
 
 
- Algebraic
                          Solutions of nth Order Linear Differential
                          Equations,  Proceedings of the
                          Queen's University 1979 Conference on Number
                          Theory, Queens Papers in Pure and Applied
                        Mathematics, (54), pp. 379-420. 
 
 1977
 
 
- Functions
                          Satisfying Elementary Relations,, 
                          Transactions of the American Mathematical
                          Society, 227, 1977, 185-206. 
 
 
- On
Elementary,
                          Generalized Elementary, and Liouvillian
                          Extension Fields (with M. Rosenlicht), in
                         Contributions to Algebra, (H. Bass
                        et.al., ed.), Academic Press, 1977, 329-342 . 
 
 1976
 
 
- Solutions of
                          Linear Differential Equations in Function
                          Fields of One Variable,  Proceedings
                          of the American Mathematical Society, 54,
                        January 1976, 69-72. 
 
 1975
 
 
- Elementary
                          Solutions of Differential Equations, 
                          Pacific Journal of Mathematics,  59(2),
                        1975, 535-547
 
 
                      
                      
                      
                     
              
                        Michael Singer's Home Page
                         
            Comments on
                Frobenius's article "Uber algebraisch integrirbare
                lineare Differentialgleichungen''  In this paper,
              Frobenius considers homogeneous linear differential
              equations $L(y) = 0$ with coefficients in $\CX(x)$ such
              that every solution can be expressed as a rational
              function in one of the solutions. Among other things, he
              shows that if the equation is irreducible and of order
              greater than or equal to 3, then all solutions are
              algebraic. After reading Frobenius’s paper, I realized
              that some of his arguments could be replaced with results
              from "On the algebraic dependence of holonomic functions",
              #89 below. In this note, I use those results and some of
              Frobenius’s arguments to prove his result. I then discuss
              Frobenius’s arguments.