ISOTONIC CLOSURE FUNCTIONS ON A LOCALE

Document Type : Original Manuscript

Authors

1 Department of Basic Sciences, Birjand University of Technology, P.O. Box 226, Birjand, Iran.

2 Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, P.O. Box 397, Sabzevar, Iran.

Abstract

In this paper, we introduce and study isotonic closure functions on a locale. These are pairs of the form $(L, \underline{{\mathrm{cl}}}_L)$, where
$L$ is a locale and $\underline{{\mathrm{cl}}}_L\colon \mathcal{S}\!\ell(L) \rightarrow \mathcal{S}\!\ell(L)$
is an isotonic closure function on the sublocales of $L$. Moreover, we introduce generalized
$\underline{{\mathrm{cl}}}_L$- closed sublocales in isotonic closure locales and discuss some of their properties. Also, we introduce and study the category $ \textbf{ICF} $ whose objects and morphisms are isotonic closure functions $(L, \underline{{\mathrm{cl}}}_L)$ and localic maps, respectively.

Keywords


 1. Ch. Boonpok, Generalized Closed Sets in Isotonic Spaces, Int. Journal of Math. Analysis, 5(5) (2011), 241–256.
 
2. M. M. Day, Convergence, closure and neighborhood, Duke Math. J., 11 (1944), 181–199.
 
3. M. J. Ferreira, J. Picado and S. M. Pinto, Remainders in pointfree topology, Topology Appl., 245 (2018), 21–45.
 
4. E. D. Habil and Kh. A. Elzenati, Connectedness in isotonic space, Turk J Math., 30 (2006), 247–262.
 
5. E. D. Habil and Kh. A. Elzenati, Topological properties in isotonic spaces, IUG Journal of Natural Studies, 16(2) (2008), 1–14.
 
6. P. C. Hammer, Extended topology: Continuity I, Portug. Math., 25 (1964), 77–93.
 
7. P. C. Hammer, Extended topology: Set-valued set functions, Nieuw Arch. Wisk. III, 10 (1962), 55–77.
 
8. F. Hausdorff, Gestufte Raume, Fund. Math., 25 (1935), 486–502.
 
9. N. Levine, Generalized closed sets in topology, Rend. Circ. Mat. Palermo., 19 (1970), 89–96.
 
10. J. Picado and A. Pultr, Frames and locales topology without points, Birkhäuser, New York, 2012.
 
11. J. Picado and A. Pultr, On equalizers in the Category of locales, Appl. Categ. Structures, 29 (2011), 267–283.
 
12. J. Slapal, Closure operations for digital topology, Theoret. Comput. Sci., 305 (2003), 457–471.
 
 13. B. M. R. Stadler and P. F. Stadler, Basic properties of closure spaces, J. Chem. Inf. Comput. Sci., 42 (2002), 577–585.
 
14. B. M. R. Stadler and P. F. Stadler, Higher separation axioms in generalized closure spaces, Commentationes Mathematicae Warszawa, 43 (2003), 257–273.