On the determination of fuzzy topological spaces and fuzzy neighbourhood spaces by their level-topologies
โ Scribed by P. Wuyts
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 51 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0165-0114
No coin nor oath required. For personal study only.
โฆ Synopsis
In the above mentioned paper, the remarks 5.2, as stated, are erroneous. Part (b) of it should read "CL(U) E fl,~l~,i-~t To(x) means exactly that p(x) must be an open neighbourhood of x in (X, FL-,))". Part (a) should be postponed, under a modified form, until after Proposition 5.4. This has no bearing on the proof of 5.3, so this proposition remains valid (giving N*(x) the same meaning as in 5.1). The proof of 5.4 must be slightly adapted as follows. In parts (a), (b), (c) of that proof, &(x) should stand, temporarily, for {~*;~:Z,+2Xdecreasing and VCYEZ~:~((Y) ~&l,,~-~l 'Q(x)}.
If then N(x) is the (non-empty) set of all fuzzy neighbourhood systems on X with level-topologies (F= = l,(t('Y(x)))),;,,, and (X(X)),,~ is an arbitrary member of N(X), then part (a) of the proof in fact means that X(x) c J&(X). The rest of the proof remains unaltered, and parts (a), (b), (c) together give X(x) c N*(x) c Y(x). From this it follows:
- by arbitrariness of X(x) that X(x) = N&x) = V(x); 2. that N(X) is a singleton (i.e. in fact, Theorem 5.5), and therefore that N,(x) can be given again the same meaning as in 5.3; 3. (modified remark 5.2(a)) (C&$(x)),,, is a basis for (Sr(x)& and C&(x) = "c"(x), but only if (Fa)nel, is a descending chain that has the (LT)-property.
It should be noted also that in Remark 3.4(c) there is an evident but annoying misprint: Fm should, after the signs tl and U, always read TO.
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