Abstract
Inspired by the work of S. Kaplan about positive/negative conditional rewriting, we investigate initial semantics for algebraic specifications with Gentzen-formulas. Since the standard initial approach is limited to conditional equations (i.e. positive Horn-formulas), the notion of semi-initial and quasi-initial algebras is introduced and it is shown that all specifications with (positive) Gentzen-formulas admit quasi-initial models.
The whole approach is generalized to the parametric case where quasi-initiality generalizes to quasi-freeness. Since quasi-free objects need not be isomorphic, the persistency requirement is added to obtain a unique semantics for many interesting practical examples. Unique persistent quasi-free semantics can be described as a free construction when the parameter category is restricted to injective homomorphisms.
An example which does not admit a correct initial semantics but a correct unique persistent quasi-initial semantics demonstrates that the concepts introduced in this paper might be of some importance w.r.t. practical applications.
This work has been partly supported by the German Ministry of Research and Technology (BMFT) as part of the compound project ”KORSO — Korrekte Software“.
Preview
Unable to display preview. Download preview PDF.
References
K. Apt, H. Blair, and A. Walker. Towards a theory of declarative knowledge. In J. Minker, editor, Foundations of Deductive Databases and Logic Programming, Morgan Kaufmann, Los Altos, 1987.
M. Broy, W. Dosch, H. Partsch, P. Pepper, and M. Wirsing. Existential quantifiers in abstract data types. In H. A. Maurer, editor, Sixth International Colloquium on Automata, Languages, and Programming, pages 73–87, Springer Lecture Notes on Computer Science 71, Berlin, 1979.
S. Bratella and G. File. A completeness result for SLDNF resolution. Technical Report Rapporto Interno Dip 9, Dipartimento di Mathematica, Universita di Padova, 1989.
H. Ehrig, I. Claßen, P. Boehm, W. Fey, M. Korff, and M. Löwe. Algebraic concepts for software development in ACT ONE, ACT TWO, and LOTOS. In GI Tagung Softwareentwicklung, pages 201–224, Springer Informatik Fachberichte 212, Berlin, 1989.
H. Ehrig and B. Mahr. Fundamentals of Algebraic Specifications 1. Monographs in Computer Science, Springer, Berlin, 1985.
H. Ehrig and B. Mahr. Fundamentals of Algebraic Specifications 2. Monographs in Computer Science, Springer, Berlin, 1990.
J. A. Goguen. What is unification? A categorical view of substitution, equation, and solution. Technical Report CSLI-88-124, Center for the Study of Languages and Information, 1988.
J. A. Goguen, J. W. Thatcher, and E. G. Wagner. An Initial Algebra Approach to the Specification, Correctness, and Implementation of Abstract Data Types. Research Report RC 6487, IBM T. J. Watson Research Center, Yorktown Heights, 1976. Also in: Current Trends in Programming IV: Data Structuring (ed. R.Yeh), Prentice Hall, 80–149 (1978).
J. V. Guttag. The specification and application to programming of abstract data types. PhD thesis, University of Toronto, 1975.
D. Hofbauer and R. Kutsche. Grundlagen des machinellen Beweisens. Vieweg, Braunschweig/Wiesbaden, 1989.
H. Herrlich and G. Strecker. Category Theory. Allyn and Bacon, Rockleigh, New Jersey, 1973.
S. Kaplan. Positive/negative conditional rewriting. In S. Kaplan and J. P. Jouannaud, editors, Conditional Term Rewriting Systems, pages 129–143, Springer Lecture Notes in Computer Science 308, Berlin, 1988.
S. MacLane. Categories for the Working Mathematician. Springer, Berlin, 1971.
A. I. Mal'cev. Algebraic Systems. Springer, Berlin, 1973. translated from the original edition 1970.
B. Mahr and J.A. Makowski. Characterizing specification languages which admit initial semantics. Technical Report 232, Technion Haifa, 1982. Also in Theoretical Computer Science, 31:49–59, 1984.
H. Reichet. Behavioural equivalence — a unifying concept for initial and final specification methods. In Third Hungarian Computer Science Conference, pages 27–39, 1981.
H. Reichel. Initial Compulability, Algebraic Specifications, and Partial Algebras. Akademie-Verlag, Berlin, 1987.
W. Wechler. Universal algebra for computer scientists. Technical Report, Technische Universität Dresden, Sektion Mathematik, 1988. To be published as a book by Springer.
M. Wirsing. Structured algebraic apecification: a kernel language. Theoretical Computer Science, 43:123–250, 1986.
M. Wirsing. Algebraic Specification. Research Report MIP-8914, University of Passau, 1989. Updated version also in “Handbook of Theor. Comp. Sci. Vol. B, Elsevier, Amsterdam, 1990.
U. Wolter. Deduction in partial equational Horn theories. Journal of Information Processing and Cybernetics (EIK), 27(2):85–128, 1991.
S. N. Zilles. Algebraic specification of data types. Technical Report, MIT, Project MAC Progress Report 11, pages 28–52, 1974.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1992 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Wolter, U., Löwe, M. (1992). Beyond conditional equations. In: Raoult, J.C. (eds) CAAP '92. CAAP 1992. Lecture Notes in Computer Science, vol 581. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-55251-0_19
Download citation
DOI: https://doi.org/10.1007/3-540-55251-0_19
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-55251-2
Online ISBN: 978-3-540-46799-1
eBook Packages: Springer Book Archive