Skip to main content
Log in

Theo: An interactive proof development system

  • Programming Logic
  • Published:
BIT Numerical Mathematics Aims and scope Submit manuscript

Abstract

This paper presents an interactive, tactic-driven, proof development system, a Theorem Prover calledTheo. Both the meta and the object levels of our theorem prover are logics presented in Typol. Typol is the programming language that implements Natural Semantics, a semantics developed at Inria and pioneered by G. Plotkin under the name Structural Operational Semantics. So Theo is written in Typol and helps the user to build proofs in an object logic also written in Typol. Tactics and tacticals are written in Typol. Other important features of Theo are the form chosen for representing proofs, and the way proofs are performed. The internal form of the proofs is very compact, expressed with combinators, that can be related to the λ-calculus used in Automath and its descendants. Meanwhile, Theo performs proofs by a pure calculus on proofs, using a resolution rule. Proofs may be incomplete and may contain logical variables. Theo is developed under the Centaur system, as well as Typol. This system provides a modern graphic man-machine interface that Theo uses, for the user's advantage.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. A. Avron,Simple Consequence Relations, Edinburgh Report ECS-LFCS-87-30, June 1987.

  2. A. Avron, F. Honsell, A. Mason,Using typed λ-calculus to implement formal systems on a machine, Edinburgh Report ECS-LFCS-87-31, July 1987.

  3. J. Barwise,The Handbook of Mathematical Logic, North-Holland, Amsterdam, 1977, reprinted in 1983.

    Google Scholar 

  4. Th. Coquand,An analysis of Girard's paradox, Proc. of the first ACM-IEEE Symp. on Logic In Computer Science, Cambridge, Ma, USA, June 1986.

  5. Th. Coquand,The tactics Theorem Prover, User's guide, inCalculus of Constructions, Documentation and Users' guide, Version 4.10, July 1st 1989.

  6. R. L. Constable et al.,Implementing Mathematics with the Nuprl Proof Development System, Prentice-Hall, 1986.

  7. J. Despeyroux,Proof of translation in natural semantics, Inria Research Report 514, april 1986, also in the Proc. of the first ACM-IEEE Symp. on Logic In Computer Science, Cambridge, Ma, USA, June 1986.

  8. J. Despeyroux,First experiments with theorem proving in Centaur: the Calculus of Constructions, the Edinburgh Logical Framework, and Theo, in Esprit project 348 GIPE. Third annual review report, January 1988.

  9. J. Despeyroux,Theo: an interactive Typol theorem prover, Inria Research Report 887, August 1988.

  10. Th. Despeyroux,Typol: a formalism to implement Natural Semantics, Inria Technical Report 94, mars 1988.

  11. A. Felty and D. Miller,Specifying theorem provers in a higher-order logic programming language, Ninth Conference on Automated Deduction, 1988, and Report MS-CIS-88-12, University of Pennsylvania, February 1988.

  12. G. Gentzen,The Collected Papers of Gerhard Gentzen, edited by M. E. Szabo, inStudies in Logic and the Foundations of Mathematics, North-Holland, Amsterdam, 1969.

    Google Scholar 

  13. T. G. Griffin,An Environment for Formal Systems, Report 087-022005, Cornell University, August 1987.

  14. R. Harper, F. Honsell and G. Plotkin,A Framework for defining Logics, Proc. of the second ACM-IEEE Symp. on Logic In Computer Science, Cornell, USA, 1987.

  15. L. Hascoët,A tactic-driven system for building proofs, Inria Research report 770, Dec. 1987. Also in the Proc. of the 7th seminarProgrammation en Logique, Tregastel, May 1988.

  16. G. Huet,A uniform approach to Type Theory, Inria Research Report 795, February 1988.

  17. J. P. Jouannaud and C.Kirchner,Solving Equations in Abstract Algebras: A Rule-Bases survey of Unification. March 31, 1990.

  18. G. Kahn,Natural Semantics, Proc. of Symp. on Theoretical Aspects of Computer Science, Passau, Germany, February 1987, also Inria Research Report 601, Feb. 1987.

  19. D. Miller and G. Nadathur,A logic programming approach to manipulating formulas and programs, Report MS-CIS-87-113, University of Pennsylvania, December 1987.

  20. G. Nadathur,A higher-order logic as the basis for logic programming, Ph.D. dissertation, University of Pennsylvania, Dec. 1986, also Report MS-CIS-87-48, University of Pennsylvania, June 1987.

  21. L. C. Paulson,Logic and computation. Interactive proof with Cambridge LCF, Cambridge Tracts in Theoretical Computer Science 2, 1987.

  22. L. C. Paulson,The representation of logics in higher-order logic, Cambridge Technical Report 113, 1987.

  23. L. C. Paulson,The foundation of a generic theorem prover, Cambridge Technical Report 130, March 1988 and Journal of Automated Reasoning, vol. 5, 1989, pp. 363–397.

    Google Scholar 

  24. G. D. Plotkin,A structural approach to operational semantics, Aarhus Report DAIMI FN-19, 1981.

  25. D. Prawitz,Natural Deduction, a Proof-Theoretical Study, Almqvist & Wiksell, Stockholm, 1965.

    Google Scholar 

  26. D. Prawitz,Ideas and results in Proof Theory, Proc. of the 2nd. Scand. Logic Congress, North Holland, 1971.

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Despeyroux, J. Theo: An interactive proof development system. BIT 32, 15–29 (1992). https://doi.org/10.1007/BF01995105

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01995105

Subject classification

Keywords

Navigation