Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-06-07T22:56:50.989Z Has data issue: false hasContentIssue false

Injectivity in the Topos of Complete Heyting Algebra Valued Sets

Published online by Cambridge University Press:  20 November 2018

Denis Higgs*
Affiliation:
University of Waterloo, Waterloo, Ontario
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Let be a complete Heyting algebra (CHA). An -valued set is a pair (X, δ) where X is a set and δ is a function from X × X to such that

for all x, y z in X. -valued sets form a category as follows: a morphism from (X, δ) to (Y, δ) is a function f from X × Y to such that

  • (i) f(x) ∧ δ(x, x′) ≦ f(x′, y), f(x, y) ∧ δ(y, y′) ≧ f(x, y′),

  • (ii) f(x, y)f(x, y′) ≦ δ(y, y′), and

  • (iii)

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1984

References

1. Ebrahimi, M. M., Algebra in Grothendieck topos: injectivity in quasi-equaîional classes, J. Pure Appl. Algebra 26 (1982), 269280.Google Scholar
2. Fourman, M. P. and Scott, D. S., Logic and sheaves, in Applications of sheaves, proceedings, 1977 (Fourman, M., Mulvey, C., and Scott, D., eds.), 302401, Lecture Notes in Mathematics 753 (Springer-Verlag, Berlin, Heidelberg, New York, 1979).Google Scholar
3. Freyd, P. J., Aspects oftopoi, Bull. Austral. Math. Soc. 7 (1972), 176.Google Scholar
4. Higgs, D., Boolean-valued equivalence relations and complete extensions of complete boolean algebras, Bull. Austral. Math. Soc. 3 (1970), 6572.Google Scholar
5. Higgs, D., A category approach to boolean valued set theory, preprint, University of Waterloo (1973).Google Scholar
6. Johnstone, P. T., Topos theory (Academic Press, London, New York, San Francisco, 1977).Google Scholar
7. Johnstone, P. T., Linton, F. E. J. and Paré, R., Injectives in topoi, II: Connections with the axiom of choice, in Categorical topology, proceedings, 1978 (Herrlich, H. and Preuβ, G., eds.), 207216, Lecture Notes in Mathematics 719 (Springer-Verlag, Berlin, Heidelberg, New York, 1979).Google Scholar
8. Kock, A. and Mikkelson, C. J., Non-standard extensions in the theory of toposes, Aarhus Universitet Preprint Series (1971/72), No. 25.Google Scholar
9. Linton, F. E. J., Injectives in topoi, III: Stability under coproduits, Bull. Acad. Polon. Sci. Sér. Sci. Math. Astronom. Phys. 29 (1981), 341347.Google Scholar
10. Linton, F. E. J., and Paré, R., Injectives in topoi, I: Representing coalgebras as algebras, in Categorical topology, proceedings, 1978 (Herrlich, H. and Preuβ, , eds.), 196206, Lecture Notes in Mathematics 719 (Springer-Verlag, Berlin, Heidelberg, New York, 1979).Google Scholar
11. Meyer, H.-M., Injektive Objekte in Topoi, Dissertation, Eberhard-Karls-Universitàt zu Tubingen (1974).Google Scholar
12. Rosser, J. B., Simplified independence proofs (Academic Press, London, New York, San Francisco, 1969).Google Scholar
13. Scott, D. S., Lectures on boolean-valued models for set theory, Summer School in Set Theory, Los Angeles (1967).Google Scholar
14. Tierney, M., Sheaf theory and the continuum hypothesis, in Toposes, algebraic geometry and logic (Lawvere, F. W., ed.), 1342, Lecture Notes in Mathematics 274 (Springer-Verlag, Berlin, Heidelberg, New York, 1972).Google Scholar