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A sufficient condition for completability of partial combinatory algebras

Published online by Cambridge University Press:  12 March 2014

Andrea Asperti
Affiliation:
Dipartimento di Matematica, P.Zza di Porta S.Donato 5, Bologna, Italy E-mail: [email protected]
Agata Ciabattoni
Affiliation:
Corso di Laurea in Scienze dell'Informazione, Università degli Studi di Bologna, Via Sacchi 3, Cesena, Italy E-mail: [email protected]

Abstract

A Partial Combinatory Algebra is completable if it can be extended to a total one. In [1] it is asked (question 11, posed by D. Scott, H. Barendregt, and G. Mitschke) if every PCA can be completed. A negative answer to this question was given by Klop in [12, 11]; moreover he provided a sufficient condition for completability of a PCA (M, •, K,S) in the form of ten axioms (inequalities) on terms of M. We prove that just one of these axiom (the so called Barendregt's axiom) is sufficient to guarantee (a slightly weaker notion of) completability.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1997

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References

REFERENCES

[1]Open problems; Swansea λ-calculus meeting, 21 September 1979, Bulletin of the EATCS (1980), no. 10.Google Scholar
[2]Asperti, A. and Ciabattoni, A., Effective applicative structures, Proceedings of the sixth biennial conference on Category Theory in Computer Science (CTCS'95) (Cambridge) (Goos, G., Hartmanis, J., and van Leeuwen, J., editors), LNCS, vol. 953, 08 1995, pp. 8195.CrossRefGoogle Scholar
[3]Asperti, A. and Ciabattoni, A., On completability of partial combinatory algebras, Proceedings of the Italian Conference on Theoretical Computer Science, Ravello, Italy, 11 1995, to appear.Google Scholar
[4]Barendregt, H., Normed uniformly reflexive structures, λ calculus and computer science theory (Bohm, C., editor), LNCS, vol. 37, Springer-Verlag, 1975, pp. 272286.CrossRefGoogle Scholar
[5]Barendregt, H., The lambda calculus, North-Holland, 1984.Google Scholar
[6]Beeson, M. J., Foundation of constructive mathematics, Springer-Verlag, 1985.CrossRefGoogle Scholar
[7]Bethke, I., On the existence of extensional partial combinatory algebras, this Journal, vol. 52 (1987), no. 3, pp. 819833.Google Scholar
[8]Bethke, I. and Klop, J. W., Collapsing partial combinatory algebras, CWI Internal Report, vol. CS-R9520 (1995).Google Scholar
[9]Bethke, I., Klop, J. W., and de Vrijer, R., Completing partial combinatory algebras with unique head normal forms, CWI Internal Report, vol. CS-R9544 (1995).Google Scholar
[10]Hindley, J. R. and R. Seldin, J., Introduction to combinators and isλ-calculus, London Mathematical Society Student Texts, vol. 1 (1990).Google Scholar
[11]Klop, J. W., personal communication.Google Scholar
[12]Klop, J. W., Extending partial combinatory algebras, Bulletin of the European Association for Theoretical Computer Science, vol. 16 (1982), pp. 472482.Google Scholar