## Separation axioms, subspaces and sums in fuzzy topology.(English)Zbl 0543.54006

Separation axioms are extended to fuzzy topological spaces. The authors define $$FT_ 0$$, $$FT_ 1$$, $$FT_ s$$, $$FT_ 2$$, $$FT_ 3$$ and $$FT_ 4$$ spaces, and, by means of counterexamples, they point out the non- coincidence of the different notions of separation. The remarkable deviation from ordinary topology is found in the non-productivity of the regularity property; localized separation axioms are also introduced in fuzzy setting. The authors also study the hereditary and the additivity behaviour of $$C_ I$$, $$C_{II}$$, separability and some types of compactness in fuzzy setting.
Reviewer: S.Ganguly

### MSC:

 54A40 Fuzzy topology 54D10 Lower separation axioms ($$T_0$$–$$T_3$$, etc.) 54D30 Compactness 54B10 Product spaces in general topology 54B35 Spectra in general topology
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### References:

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