Title
More on Subfitness and Fitness
Abstract
The concepts of fitness and subfitness (as defined in Isbell, Trans. Amer. Math. Soc. , 353–371, ) are useful separation properties in point-free topology. The categorical behaviour of subfitness is bad and fitness is the closest modification that behaves well. The separation power of the two, however, differs very substantially and subfitness is transparent and turns out to be useful in its own right. Sort of supplementing the article (Simmons, Appl. Categ. Struct. , 1–34, ) we present several facts on these concepts and their relation. First the “supportive” role subfitness plays when added to other properties is emphasized. In particular we prove that the numerous Dowker-Strauss type Hausdorff axioms become one for subfit frames. The aspects of fitness as a hereditary subfitness are analyzed, and a simple proof of coreflectivity of fitness is presented. Further, another property, prefitness, is shown to also produce fitness by heredity, in this case in a way usable for classical spaces, which results in a transparent characteristics of fit spaces. Finally, the properties are proved to be independent.
Year
DOI
Venue
2015
10.1007/s10485-014-9366-7
Applied Categorical Structures
Keywords
Field
DocType
Frame,Locale,Sublocale lattice,Fit frame,Subfit frame,Prefit frame,Hausdorff property,Nearness,Quasi-Nearness,06D22,54B05,54D10,54E15,54E17
USable,Topology,Discrete mathematics,Axiom,Categorical variable,struct,sort,Pure mathematics,Hausdorff space,Mathematics
Journal
Volume
Issue
ISSN
23
3
0927-2852
Citations 
PageRank 
References 
2
0.60
2
Authors
2
Name
Order
Citations
PageRank
Jorge Picado12010.18
Ales Pultr27224.12