STRUCTURE SPACE
Dr.D.Amsaveni1, S. Meenakshi2 and J. Tamilmani3
1
Department of Mathematics (Assistant Professor), Sri Sarada College for Women, Salem - 636 016, Tamilnadu, India
2,3
Department of Mathematics (Research Scholars),Sri Sarada College for Women, Salem - 636 016, Tamilnadu, India
Abstract
In this paper, a new class of sets called **
X
FQ pre semi-
λ
closed sets in fuzzy scalable structure space is introduced and its possible interrelations with other type of **X
FQ closed sets are studied with necessary counter examples. Similar types of interrelations for continuous functions are also been discussed.
Keywords: Fuzzy scalable structure space, **
X
FQ pre semi-
λ
closed set, **X
FQ continuous function. AMS Mathematics Subject Classification (2010): 54A40, 03E72
I. Introduction
Fuzzy topological spaces are enriched by additional structures in order to give a more realistic representation of real life phenomena and computational process and at the same time, to provide for utilization of the powerful technique need a scale because all measurements and the majority of computations are performed in a definite space and problems of scalability are important both for physical theories and computational algorithms. The fuzzy concepts have penetrated almost all branches of Mathematics since the introduction of the concept of fuzzy set by Zadeh [11]. The theory of fuzzy topological spaces was introduced and developed by Chang [6]. M.Burgin [4 , 5] introduced the concept of discontinuity structures in topological spaces and also investigated the concept of scale
Q
in a topological space. This structure serves as a scale for the initial topology on X. In this paper, the notion of **X
FQ pre semi-
λ
closed sets and FQ*X* continuous functions in fuzzyscalable structure spaces are introduced and studied. Some of their properties are investigated.
1. Preliminaries
Definition 1.1 [11]
Let X be a non-empty set and
I
be the unit interval. A fuzzy set in X is an element of the setx
I
of all functions from X toI
.Definition 1.2 [6]
A fuzzy topology is a family T of fuzzy sets in
(
X,T)
which satisfies the following conditions:(a)
0
,
1
∈
T
;
(b)
if
A
,
B
∈
T
,
then
A
I
B
∈
T
;
Then, T is called a fuzzy topology for X and the pair
(
X,T)
is a fuzzy topological space (abbreviated as fts). Every member of T is called a T-open fuzzy set. A fuzzy set is T-closed if and only if its complement is T-open.Definition 1.3
A fuzzy set
µ
of a fts(
X,T)
is called:1. a fuzzy pre-open set [3] if
µ
≤
int(
cl
(
µ
))
and a fuzzy pre-closed set ifcl
(int(
µ
))
≤
µ
.
2. a fuzzy semi-open set [2] ifµ
≤
cl
(int(
µ
))
and a fuzzy semi-closed set ifint(
cl
(
µ
))
≤
µ
.
3. a fuzzy semi-pre open set [9] if
µ
≤
cl
(int(
cl
(
µ
)))
and a fuzzy semi-pre closed if.
)))
(int
int(
cl
µ
≤
µ
4. a fuzzy regular open set [2] if
µ
=
int(
cl
(
µ
))
and a fuzzy regular closed set ifµ
=
cl
(int(
µ
)).
5. a fuzzy generalized open (fg-open) set [1] ifint(
µ
)
≤
ω
whenever µ≤ω and ω is fuzzy open setin (X,T). The complement of fuzzy g-open set is called fuzzy g-closed set in (X,T). 6. a fuzzy b-open (fb-open) set [2] iff
µ
≤
(int
cl
µ
)
∨
(
cl
int
µ
)
and a fuzzy b-closed 7. (fb-closed) set iffµ
≥
(
cl
int
µ
)
∧
(int
cl
µ
).
8. a fuzzy t-set [10] if
int(
µ
)
=
int
cl
(
µ
)
.9. a fuzzy B-set [10] if
µ
=µ
1∧µ
2whereµ
1 is fuzzy open andµ
2 is a fuzzy t-set.a. The class of all fuzzy pre-open (resp. fuzzy semi-open, fuzzy semi-pre open, fuzzy regular open, fuzzy generalized open, fuzzy b-open, fuzzy t-set and fuzzy B set) sets in a fuzzy topological space
(
X,T)
is denoted by FPO(X) (resp. FSO(X), FSPO(X), FRO(X), FGO(X), FbO(X), Ft(X) and FB(X) ).Definition 1.4 [7]
A subset B of a space X is a Λ-set ifB=BΛ, where BΛ=
∧
{
U U >BU∈T}
,, .
Definition 1.5 [7]
A subset A of a space X is called
λ
-closed if A = B∧C, where B is a Λ-set and C is a closed set.Definition 1.6 [7]
A subset A of a space X is called
λ
-open if Ac = X\A isλ
-closed.Definition 1.7[9]
Let
µ
be a fuzzy set in a fts X. Then fuzzy semi pre - interior ofµ
is denoted and defined by spint(µ
) =∨{
ω
:ω
≤µ
,µ
∈FSPO(X)}
.Definition 1.8[8]
A fuzzy set
µ
of a fts X is called a fuzzy pre semi open set if spint(µ
)≥ ω, wheneverω
µ≥ and ωis a fuzzy g-closed set in ( X,T ). The class of all fuzzy pre semi open sets is denoted by FPSO(X).
The complement of a fuzzy pre semi open set is called a fuzzy pre semi closed set in ( X, T ).
Definition 1.9 [5]
Let X be a topological space with a topology TX and TQ be a subset of TX, i.e., TQ consists of open sets from X.
A scale or discontinuity structure QX = Q on X is a mapping X →
TQ
2 that satisfies the following conditions:
(SC1) For all points x from X, if A is an element of Q(x), then x∈A.
2. Fuzzy Pre semi -
λ
closed sets in fuzzy scalable structure space
Definition 2.1
Let X be a non empty set, τi:i∈J be the fuzzy topologies associated with X and let *
X
τ be
the collection of all fuzzy open sets of(X,τi)and a function QX:
*
X
X→τ be the fuzzy scale. A fuzzy scalable structure is denoted by **
X
Q and defined by **
{
0,1}
*X
X Q
Q = U where
{
Q x x X}
QX = X( ): ∈
* .
Definition 2.2
Let X be a non empty set, *
X
τ be the collection of all fuzzy open sets of X and **
X
Q be a fuzzy scalable structure on X. Then, the triad
(
X
,
τ
X*,Q*X*)is called a fuzzy scalable structure space.Every member of **
X
Q is called a fuzzy **
X
Q open set (briefly, **
X
FQ open). Its complement is said to be a fuzzy **
X
Q closed set (briefly, **
X
FQ closed).
Definition 2.3
Let
(
,
*, **)X X Q
X
τ
be a fuzzy scalable structure space. The fuzzy **X
Q interior and fuzzy **
X
Q closure of a fuzzy set
µ
of X are defined and denoted as follows:(i) **int(µ)
{
ω:ω ** ω µ}
.≤ =
∨
isaFQ opensetandFQX X
(ii) FQ*X*cl(µ)=
∧
{
ω:ωisaFQ*X*closed setandω≥µ}
.Definition 2.4
A fuzzy subset
µ
of a fuzzy scalable structure space(
X
,
τ
*X,Q*X*) is called: 1. a fuzzy **X
Q pre-open (in short, **
X
FQ pre-open) set, if **int( ** ( ))
µ
µ≤FQX FQXcl and a fuzzy * *
X
Q
pre-closed (in short, **
X
FQ pre-closed) set if FQX**cl(FQ*X*int(µ))≤µ. 2. a fuzzy **
X
Q semi-open (in short, **
X
FQ semi-open) set if µ ≤FQ*X*cl(FQX**int(µ))and a fuzzy * *
X
Q semi-closed (in short, **
X
FQ semi-closed) set if FQ*X*int(FQ*X*cl(µ))≤µ.
3. a fuzzy **
X
Q semi-pre open (in short, **
X
FQ sp-open) set if ** ( **int( ** ( )))
µ
µ ≤FQXcl FQX FQXcl and a fuzzy **
X
Q semi-pre closed (in short, **
X
FQ sp-closed) if FQX**int(FQX**cl(FQ*X*intµ)))≤µ. 4. a fuzzy **
X
Q regular open (in short, **
X
FQ regular-open) set if **int( ** ( ))
µ
µ =FQX FQXcl and a fuzzy *
*
X
Q regular closed (in short, **
X
FQ regular-closed) set if ** ( **int( )).
µ µ = FQXcl FQX
5. a fuzzyQ*X* generalized open (in short,
* *
X
FQ g-open) set if **int(µ)≤ω
X
FQ whenever µ≤ω and
ω is fuzzy Q*X*open set in ( , **) X
Q
X . The complement of fuzzyQ*X*g-open set is called fuzzy
* *
X
Q
g-closed (in short,FQ*X*g-closed) set in
(
,
*, **) X X QX
τ
.6. a fuzzyQ*X* b-open (in short,
* *
X
FQ b-open) set ifµ ≤(FQX**intFQX**clµ)∨(FQ*X*clFQ*X*intµ)and a
fuzzyQX** b-closed (in short
* *
X
FQ b-closed) set ifµ ≥(FQ*X*clFQX**intµ)∧(FQ*X*intFQX**clµ).
7. a fuzzyQ*X* t-set (in short,
* *
X
FQ t-set) if **int(µ) **int ** (µ) cl FQ FQ
FQX = X X .
8. a fuzzy **
X
Q B-set (in short, **
X
FQ B-set) if
µ
=µ
1∧µ
2whereµ
1 is a **X
FQ t - set and
µ
2is a **X
FQ open set.
The class of all **
X
FQ pre-open (resp. **
X
FQ semi-open, **
X
FQ semi-pre open, **
X
FQ regular open, *
*
X
FQ generalized open, **
X
FQ b open, **
X
FQ t-set and **
X
FQ B set) sets in a fuzz scalable structure space
(
X
,
τ
*X,Q*X*) is denoted by* *
X
FQ PO(X) (respectively **
X
FQ SO(X), **
X
FQ SPO(X), **
X
FQ
RO(X), **
X
FQ GO(X), **
X
FQ bO(X), **
X
FQ t(X) and **
X
Definition 2.5
A fuzzy subset µof a fuzzy scalable structure space
(
X
,
τ
*X,Q*X*) is called: 1. a fuzzyQ*X*- Λset (in short,* *
X
FQ - Λset) if µ= **µΛ
X
FQ , whereFQ*X*µΛ=
∧
{
ω,ω>µ,ω∈QX**}
.2. a fuzzyQ*X*pre semi -Λset (in short,
* *
X
FQ pre semi -Λset) ifµ=FQXPSµΛ
* *
,
where
{
, , ()
}
. ** *
*
X PSO FQ PS
FQX =
∧
> ∈ XΛ ω ω µ ω µ
3. a fuzzy Q*X* regular - Λ set (in short,
* *
X
FQ regular - Λ set) if µ=FQXRµΛ
* *
, where
{
, , ** ()
}
. **
X RO FQ R
FQX Λ =
∧
> ∈ X ω µ ω ω µ4. a fuzzy Q*X* b - Λ set (in short,
* *
X
FQ b - Λ set) if µ =FQXbµΛ
* *
, where
{
, , ** ()
}
. **
X bO FQ b
Q
F X =
∧
> ∈ XΛ ω ω µ ω µ
Definition 2.6
A fuzzy subset µof a fuzzy scalable structure space *, **)
,
(
X
τ
X QX is called:1. a fuzzy **
X
Q
λ
-closed (in short, **X
FQ
λ
- closed) ifµ
=µ
1∧µ
2, whereµ
1 is a **X
FQ Λ-set and
2
µ
is a **X
FQ closed set. 2. a fuzzy **
X
Q pre semi
λ
-closed (in short, **X
FQ pre semi
λ
-closed) ifµ
=µ
1∧µ
2, whereµ
1is a **
X
FQ pre semiΛ-set and
µ
2is a **X
FQ closed set. 3. a fuzzy **
X
Q regular
λ
-closed (in short, **X
FQ regular
λ
-closed) ifµ
=µ
1∧µ
2, whereµ
1is a **
X
FQ regularΛ-set and
µ
2is a * *X
FQ closed set. 4. a fuzzy **
X
Q b -
λ
closed (in short, **X
FQ b -
λ
closed) ifµ
=µ
1∧µ
2, whereµ
1is a **X
FQ b -Λset and
µ
2is a **X
FQ closed set. The complement of a **
X
FQ
λ
-closed (resp. **X
FQ pre semi
λ
-closed, **X
FQ regular
λ
-closed and **
X
FQ b -
λ
closed) set is called a **X
FQ
λ
-open(resp. **X
FQ pre semi
λ
- open , **X
FQ regular
λ
-open and **X
FQ b -λopen).
Proposition 2.1
Every **
X
FQ -closed set in fuzzy scalable structure space
(
,
*, **)X X Q
X
τ
is a **X
FQ semi pre closed set.
Remark 2.1
The converse part of the above Proposition 2.1 need not be true as shown in the following example.
Example 2.1
Let X=
{
a,b}
be a non empty set and *X
τ
be the collection of all fuzzy open sets in X. Let }, , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X whereµ
1,µ
2,µ
3∈IX defined as; 6 . 0 ) ( , 7 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.3,µ
2(b)=0.2;µ
3(a)=0.5,µ
3(b)=0.4. Now, define *: X
X X
Q →
τ
by QX(a)=µ
1; QX(b)=µ3. Then, QX is a fuzzy scale and { 1, 3}. *µ µ =
X
Q Let
} , , 1 , 0
{ 1 3 *
*
µ µ =
X
Q be a fuzzy scalable structure on X. Clearly, the triad
(
,
*, **)X X Q
X
τ
is fuzzy scalable structure space. Here the fuzzy setµ
2 is a* *
X
FQ semi pre closed but not **
X
FQ closed.
Proposition 2.2
Every **
X
FQ semi pre closed set in fuzzy scalable structure space *, **)
,
(
X
τ
X QX is a* *
X
FQ pre semi closed set.
Remark 2.2
Example 2.2
Let X=
{
a,b}
be a non empty set and *X
τ
be the collection of all fuzzy open sets in X. Let }, , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X whereµ
1,µ
2,µ
3∈IX defined as; 3 . 0 ) ( , 2 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.7,µ
2(b)=0.7;µ
3(a)=0.3,µ
3(b)=0.4. Now, define *: X
X X
Q →
τ
by QX(a)=µ
1; QX(b)=µ3. Then, QX is a fuzzy scale and { 1, 3}. *µ µ =
X
Q Let
} , , 1 , 0
{ 1 3 *
*
µ µ =
X
Q be a fuzzy scalable structure on X. Clearly, the triad
(
,
*, **)X X Q
X
τ
is fuzzy scalable structure space. Here the fuzzy setµ
2 is a **X
FQ pre semi closed but not semi pre **
X
FQ closed.
Proposition 2.3
Every **
X
FQ closed set in fuzzy scalable structure space
(
,
*, **)X X Q
X
τ
is a **X
FQ pre semi closed set.
Remark 2.3
The converse part of the above Proposition 2.3 need not be true as shown in the following example.
Example 2.3
In example 2.1, the fuzzy set
µ
2 is a **X
FQ pre semi closed but not **
X
FQ closed.
Proposition 2.4
Every **
X
FQ regular closed set in fuzzy scalable structure space
(
X
,
τ
*X,Q*X*)is a * *X
FQ semi pre closed set.
Remark 2.4
The converse part of the above Proposition 2.4 need not be true as shown in the following example.
Example 2.4
In example 2.1, the fuzzy set
µ
2 is a **X
FQ semi pre closed but not **
X
FQ regular closed.
Proposition 2.5
Every **
X
FQ regular closed set in fuzzy scalable structure space
(
X
,
τ
*X,Q*X*)is a * *X
FQ pre semi closed set.
Remark 2.5
The converse part of the above Proposition 2.5 need not be true as shown in the following example.
Example 2.5
In example 2.1, the fuzzy set
µ
2 is **X
FQ pre semi closed but not **
X
FQ regular closed.
Proposition 2.6
Every **
X
FQ b - closed set in fuzzy scalable structure space *, **)
,
(
X
τ
X QX is a* *
X
FQ semi pre closed set.
Remark 2.6
The converse part of the above Proposition 2.6 need not be true as shown in the following example.
Example 2.6
In example 2.1, the fuzzy set
µ
2 is a **X
FQ semi pre closed but not **
X
FQ b-closed.
Proposition 2.7
Every **
X
FQ b - closed set in fuzzy scalable structure space
(
,
*, **)X X Q
X
τ
is a **X
FQ pre semi closed set.
Remark 2.7
Example 2.7
In example 2.1, the fuzzy set
µ
2 is a **X
FQ pre semi closed but not **
X
FQ b-closed.
Proposition 2.8
Every **
X
FQ closed set in fuzzy scalable structure space
(
,
*, **)X X Q
X
τ
is: 1. a **X
FQ pre semi-λclosed set 2. a **
X
FQ t-set 3. a **
X
FQ B-set 4. a **
X
FQ b-λclosed set 5. a **
X
FQ
λ
- closed set 6. a **X
FQ regular- λ closed set
Remark 2.8
The converse part of the above Proposition 2.8 need not be true as shown in the following examples.
Example 2.8
Let X=
{
a,b}
be a non empty set and *X
τ
be the collection of all fuzzy open sets in X. Let }, , , , 1 , 0
{ 1 2 4 5
1 µ µ µ µ
τ = and τ2 ={0,1,µ3}be the fuzzy topologies on X where
µ
1,µ
2,µ
3,µ
4∈IX defined asµ
1(a)=0.4,µ
1(b)=0.3;µ
2(a)=0.4,µ
2(b)=0.1;µ
3(a)=0.8,µ
3(b)=0.1;µ
4(a)=0.3,; 3 . 0 ) ( 4 b =
µ
µ
5(a)=0.3,µ
5(b)=0.1.Now, define*
: X
X X
Q →
τ
by QX(a)=µ
1;QX(b)=µ3.Then,X
Q is a fuzzy scale and { 1, 3}. *
µ µ =
X
Q Let {0,1, 1, 3} *
*
µ µ =
X
Q be a fuzzy scalable structure on X.
Clearly, the triad
(
,
*, **)X X Q
X
τ
is fuzzy scalable structure space. Here the fuzzy setω
defined by4
.
0
)
(
,
4
.
0
)
(
a
=
ω
b
=
ω
is a **X
FQ pre semi-λclosed, **
X
FQ t-set, **
X
FQ B –set and **
X
FQ b -λset but not *
*
X
FQ closed set. The fuzzy set
µ
2 is **X
FQ -λclosed but not **
X
FQ closed.
Example 2.9
Let X=
{
a,b}
be a non empty set and *X
τ
be the collection of all fuzzy open sets in X. Let }, , , 1 , 0
{ 1 2 4
1
µ
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X whereX
I ∈
4 3 2 1,
µ
,µ
,µ
µ
definedas
µ
1(a)=0.6,µ
1(b)=0.4;µ
2(a)=0.1,µ
2(b)=0.3;µ
3(a)=0.9,µ
3(b)=0.4;andµ
4(a)=0.3, 4. 0 ) ( 4 b =
µ
. Now, define *: X
X X
Q →
τ
by QX(a)=µ
2;QX(b)=µ3.Then,QX is a fuzzy scale and}. , { 2 3 *
µ µ =
X
Q Let {0,1, 2, 3} *
*
µ µ =
X
Q be a fuzzy scalable structure on X. Clearly, the triad
)
, **
*
,
(
X
τ
X QX is fuzzy scalable structure space. Here the fuzzy setω
defined by4
.
0
)
(
,
1
.
0
)
(
a
=
ω
b
=
ω
is a **X
FQ regular-λclosed but not **
X
FQ closed.
Proposition 2.9
Every **
X
FQ
λ
- closed set is a **X
FQ pre semi-
λ
closed set in fuzzy scalable structure space )., **
*
,
(
X
τ
X QXRemark 2.9
The converse part of the above Proposition 2.9 need not be true as shown in the following example.
Example 2.10
In example 2.8 the fuzzy set
µ
4is a **X
FQ pre semi-λclosed but not **
X
FQ
λ
- closed set in)
, **
*
,
(
X
τ
X QX .Proposition 2.10
Every **
X
FQ regular -
λ
closed set is a **X
FQ pre semi-
λ
closed set in fuzzy scalable structureRemark 2.10
The converse part of the above Proposition 2.10 need not be true as shown in the example.
Example 2.11
In example 2.8 the fuzzy set
µ
1is a **X
FQ pre semi-λ closed but not **
X
FQ regular -
λ
closedset in
(
X
,
τ
*X,Q*X*). Proposition 2.11Every **
X
FQ b -
λ
closed set is a **X
FQ pre semi-
λ
closed set in fuzzy scalable structure space)
, **
*
,
(
X
τ
X QX .Remark 2.11
The converse part of the above Proposition 2.11 need not be true as shown in the following example.
Example 2.12
In example 2.8 the fuzzy set ω defined by
ω
(
a
)
=
0
,
ω
(
b
)
=
0
.
6
is a **X
FQ pre semi-λ closed but not **
X
FQ b -
λ
closed set in(
,
*, **) XX Q
X
τ
.Proposition 2.12
Every **
X
FQ t-set is a **
X
FQ B-set in the fuzzy scalable structure space
(
X
,
τ
*X,Q*X*).Remark 2.12
The converse part of the above Proposition 2.12 need not be true as shown in the following example.
Example 2.13
Let X=
{
a,b}
be a non empty set and *X
τ
be the collection of all fuzzy open sets in X. Let }, , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ2,µ3}be the fuzzy topologies on X whereµ
1,µ
2,µ
3∈IX defined as; 3 . 0 ) ( , 2 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.5,µ
2(b)=0.6andµ
3(a)=0.1,µ
3(b)=0.2.
Now, define *: X
X X
Q →
τ
by QX(a)=µ
2; QX(b)=µ
2. Then, QX is a fuzzy scale and { 2}.* µ
=
X
Q Let
} , 1 , 0 { 2 *
* = µ
X
Q be a fuzzy scalable structure on X. Clearly, the triad *, **)
,
(
X
τ
X QX is a fuzzy scalablestructure space. Here the fuzzy set
µ
2is a **X
FQ B-set but not a **
X
FQ t - set.
Proposition 2.13
Every **
X
FQ regular -λ closed set is a **
X
FQ t -set in the fuzzy scalable structure space )
, **
*
,
(
X
τ
X QX .Remark 2.13
The converse part of the above Proposition 2.13 need not be true as shown in the following example.
Example 2.14
Let X=
{
a,b}
be a non empty set and τ*Xbe the collection of all fuzzy open sets in X. Let} , , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X where 13 2 1, ,
X
I ∈
µ
µ
µ
are defined as ;2 . 0 ) ( , 6 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.7,µ
2(b)=0.2;µ
3(a)=0.1,µ
3(b)=0.8 . Now define : *XX X
Q →τ by ( ) 2;
1 a =µ
QX QX1(b)=µ3.Then, QX is a fuzzy scale and { 2, 3}. *
µ µ =
X
Q Let
} , , 1 , 0
{ 2 3
* *
µ µ
= X
Q be a fuzzy scalable structure on X. Clearly, the triad
(
X
,
τ
*X,Q*X*)is a fuzzy scalable structure space. Here the fuzzy set ω defined byω
(
a
)
=
0
.
8
,
ω
(
b
)
=
0
.
2
is a **X
FQ t -set but not **
X
Proposition 2.14
Every **
X
FQ regular -λclosed set is a **
X
FQ b -λclosed set in the fuzzy scalable structure space )
, **
*
,
(
X
τ
X QX .Remark 2.14
The converse part of the above Proposition 2.14 need not be true as shown in the following example.
Example 2.15
In example 2.14, the fuzzy set ω defined by
ω
(
a
)
=
0
.
3
,
ω
(
b
)
=
0
.
2
is a **X
FQ b -λclosed set but not a **
X
FQ regular -λclosed set.
Proposition 2.15
Every **
X
FQ λ - closed set is a **
X
FQ b -λ closed set in the fuzzy scalable structure space )
, **
*
,
(
X
τ
X QX .Remark 2.15
The converse part of the above Proposition 2.15 need not be true as shown in the following example.
Example 2.16
In example 2.14, the fuzzy set
ω
defined byω
(
a
)
=
0
.
8
,
ω
(
b
)
=
0
.
2
is a **X
FQ b -λclosed set but not a **
X
FQ regular -λclosed set.
Remark 2.16
From the above discussion we have the following implications are true:
Figure: 1 Relationship between **
X
FQ - pre semi
λ
closed set and other existing **X
FQ - closed sets
3.
**X
FQ
Pre semi -
λ
continuity in fuzzy scalable structure spaces
Definition 3.1
Let
(
X
1,
τ
*X1,Q*X*1) and , ) * * * 2,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. Then thefunction f : * , **) 1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX is said to be **X
FQ continuous if for every ** 2
X
FQ - closed set in
(
X
2,
τ
X*2,QX**2) there exists a* *
1
X
FQ - closed set in
(
X
1,
τ
*X1,Q*X*1). Definition 3.2Let
(
X
1,
τ
*X1,Q*X*1) and , ) * * * 2,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. Then thefunction f : * , **) 1
,
1 1(
X
τ
X QX → , )* * * 2
,
2 2(
X
τ
X QX is said to be:1. **
X
FQ pre semi-λ continuous if for every **
2
X
FQ - closed set in
(
X
2,
τ
*X2,Q*X*2) there exists a* *
1
X
FQ
pre semi-λ- closed set in * , **)
1
,
1 1(
X
τ
X QX .* *
X
FQ pre semi-λ
closed set *
*
X
FQ t-set
* *
X
FQ B-set
* *
X
FQ b-λclosed set
* *
X
FQ –closed set
* *
X
FQ
λ
closed set* *
X
FQ regular- λ
2. **
X
FQ t -continuous if for every **
2
X
FQ - closed set in 2 * , **)
2 2
,
(
X
τ
X QX there exists a* *
1
X
FQ t -closed
set in * , **)
1
,
1 1(
X
τ
X QX .3. **
X
FQ B -continuous if for every **
2
X
FQ - closed set in
(
X
2,
τ
*X2,Q*X*2) there exists a* *
1
X
FQ B -closed
set in * , **)
1
,
1 1(
X
τ
X QX .4. **
X
FQ b -λcontinuous if for every **
2
X
FQ - closed set in
(
X
2,
τ
X*2,Q*X*2) there exists a* *
1
X
FQ b -λ
closed set in
(
X
1,
τ
X*1,QX**1).5. **
X
FQ λ- continuous if for every **
2
X
FQ - closed set in * , **)
2
,
2 2(
X
τ
X QX there exists a **1
X
FQ λ- closed
set in 1 * , **)
1 1
,
(
X
τ
X QX .6. **
X
FQ regular -λcontinuous if for every **
2
X
FQ - closed set in * , **)
2
,
2 2(
X
τ
X QX there exists a fuzzy* *
1
X
FQ regular -λclosed set in
(
X
1,
τ
X*1,Q*X*1).Proposition 3.1
Let
(
X
1,
τ
*X1,Q*X*1) and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX is **X
FQ continuous function then it is:
1. a **
X
FQ pre semi-λcontinuous function.
2. a **
X
FQ t-continuous function.
3. a **
X
FQ B-continuous function.
4. a **
X
FQ b-λcontinuous function.
5. a **
X
FQ λ- continuous function.
6. a **
X
FQ regular- λcontinuous function.
Remark 3.1
The converse part of the above Proposition 3.1 need not be true as shown in the following examples.
Example 3.1
Let X1=
{
a,b}
be a non empty set and*
1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , , , 1 , 0
{ 1 2 4 5
1
µ
µ
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where1
5 4 3 2
1, , , ,
X
I ∈
µ
µ
µ
µ
µ
are defined as
µ
1(a)=0.4,µ
1(b)=0.3;µ
2(a)=0.4,µ
2(b)=0.1;µ
3(a)=0.8,, 3 . 0 ) ( ; 1 . 0 )
( 4
3 b =
µ
a =µ
µ
4(b)=0.3;µ
5(a)=0.3,µ
5(b)=0.1.Now, define :*
1 1
1 X
X X
Q →τ by
; )
( 1
1 a =
µ
QX ( ) 3.
1 b =µ
QX Then,QX1is a fuzzy scale and { 1, 3}.
*
1 = µ µ
X
Q Let {0,1, 1, 3}
* *
1 = µ µ
X
Q be a
fuzzy scalable structure on X1. Clearly, the triad
(
X
1,
τ
X*1,Q*X*1) is a fuzzy scalable structure space.Let X2=
{
u,v}
be a non empty set and*
2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4 ={0,1,ω3}be the fuzzy topologies on X2 where 1, 2, 3 2X
I ∈
ω
ω
ω
are definedas
ω
1(u)=0.2,ω
1(v)=0.2;ω
2(u)=0.4,ω
2(v)=0.3; ω3(u)=0.6,ω
3(v)=0.7.
Now, define: *
2 2
2 X
X X
Q →τ by ( ) 1;
2 u =
ω
QX ( ) 3.
2 v =ω
QX Then,
2
X
Q is a fuzzy scale and * { 1, 3}.
2 = ω ω
X
Q Let
} , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX be a **X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ pre semi-λcontinuous and **
X
FQ b -λcontinuous
but not **
X
Example 3.2
Let X1=
{
a,b}
be a non empty set and *1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3 1X
I ∈
µ
µ
µ
are defined as; 2 . 0 ) ( , 6 . 0 ) ( 1
1 a =
µ
b =µ
µ
2(a)=0.7,µ
2(b)=0.2;µ
3(a)=0.1,µ
3(b)=0.8 . Now define: 1 * 1
1 X
X X
Q →τ by ( ) 2;
1 a =µ
QX QX1(b)=µ3.Then,QX1 is a fuzzy scale and { 2, 3}.
*
1 = µ µ
X Q Let } , , 1 , 0
{ 2 3
* *
1 = µ µ
X
Q be a fuzzy scalable structure on X1. Clearly, the triad
(
X
1,
τ
X*1,Q*X*1)is a fuzzyscalable structure space.
Let X2=
{
u,v}
be a non empty set and *2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4 ={0,1,ω3}be the fuzzy topologies on X2 where 1, 2, 3 2X
I ∈
ω
ω
ω
are definedas
ω
1(u)=0.3,ω
1(v)=0.8;ω
2(u)=0.2,ω
2(v)=0.3; ω3(u)=0.6,ω
3(v)=0.7.
Now, define: 2 * 2
2 X
X X
Q →τ by QX2(u)=
ω
1; QX2(v)=ω1. Then,QX2 is a fuzzy scale and { 1}.*
2 = ω
X Q Let } , 1 , 0 { 1 * *
2 = ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f :
(
X
1,
τ
*X1,Q*X*1)→ , )* * * 2
,
2 2(
X
τ
X QX be a* *
X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ regular -λcontinuous but not **
X
FQ continuous.
Example 3.3
Let X1=
{
a,b}
be a non empty set and *1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3 1X
I ∈
µ
µ
µ
defined as; 6 . 0 ) ( , 5 . 0 ) ( 1
1 a =
µ
b =µ
µ
2(a)=0.2,µ
2(b)=0.1;µ
3(a)=0.3,µ
3(b)=0.2.
Now, define: 1 *1
1 X
X X
Q →τ by QX1(a)=µ1; QX1(b)=µ3.Then, QX1 is a fuzzy scale and { 1, 3}.
*
1 = µ µ
X Q Let } , , 1 , 0
{ 1 3
* *
1 = µ µ
X
Q be a fuzzy scalable structure on X1. Clearly, the triad
(
X
1,
τ
X*1,Q*X*1) is a fuzzyscalable structure space.
Let X2=
{
u,v}
be a non empty set and *2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4={0,1,ω3}be the fuzzy topologies on X2 where 1, 2, 3 2X
I ∈
ω
ω
ω
defined as; 3 . 0 ) ( , 4 . 0 ) ( 1
1 u =
ω
v =ω
ω
2(u)=0.3,ω
2(v)=0.2; ω3(u)=0.7,ω
3(v)=0.6.
Now, define: 2 * 2
2 X
X X
Q →τ by ( ) 1;
2 u =ω
QX QX2(v)=ω3.Then,QX2 is a fuzzy scale and { 1, 3}.
*
2 = ω ω
X Q Let } , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f : 1 * , **)
1 1
,
(
X
τ
X QX → , )* * * 2
,
2 2(
X
τ
X QX be a* *
X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ t-continuous and **
X
FQ B-continuous but not **
X
FQ continuous.
Example 3.4
Let X1=
{
a,b}
be a non empty set and*
1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , , , 1 , 0
{ 1 2 4 5
1
µ
µ
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3, 4, 5 1X I ∈
µ
µ
µ
µ
µ
defined as
µ
1(a)=0.4,µ
1(b)=0.3;µ
2(a)=0.4,µ
2(b)=0.1;µ
3(a)=0.8,µ
3(b)=0.1;µ
4(a)=0.3, ; 3 . 0 ) ( 4 b =µ
µ
5(a)=0.3,µ
5(b)=0.1.Now, define :*
1 1
1 X
X X
Q →τ by ( ) 1;
1 a =µ
QX QX1(b)=µ3. Then,
1
X
Q is a fuzzy scale and * { 1, 3}.
1 = µ µ
X
Q Let ** {0,1, 1, 3}
1 = µ µ
X
Q be a fuzzy scalable structure
Let X2=
{
u,v}
be a non empty set and *2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4={0,1,ω3}be the fuzzy topologies on X2 where2
3 2 1, ,
X
I ∈
ω
ω
ω
defined as; 9 . 0 ) ( , 6 . 0 )
( 1
1 u =
ω
v =ω
ω
2(u)=0.4,ω
2(v)=0.3; ω3(u)=0.8, ω3(v)=0.9.
Now, define: *
2 2
2 X
X X
Q →τ by ( ) 1;
2 u =ω
QX QX2(v)=ω3.Then, QX2 is a fuzzy scale and { 1, 3}.
*
2 = ω ω
X
Q Let
} , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f :
(
X
1,
τ
*X1,Q*X*1)→ , )* * * 2
,
2 2(
X
τ
X QX be a* *
X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ λ- continuous but not **
X
FQ continuous.
Proposition 3.2
Let * , **)
1
,
1 1(
X
τ
X QX and * , **)2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f :
(
X
1,
τ
*X1,Q*X*1) → , )* * * 2
,
2 2(
X
τ
X QX is* *
X
FQ λ - continuous then it is **
X
FQ pre semi-λ
continuous. Remark 3.2
The converse part of the above Proposition 3.2 need not be true as shown in the following example.
Example 3.5
In example 3.1, the function f is **
X
FQ pre semi λ- continuous but not **
X
FQ λ- continuous.
Proposition 3.3
Let
(
X
1,
τ
*X1,Q*X*1) and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : 1 * , **)
1 1
,
(
X
τ
X QX → , )* * * 2
,
2 2(
X
τ
X QX is* *
X
FQ regular λ- continuous then it is **
X
FQ pre
semi-λcontinuous.
Remark 3.3
The converse part of the above Proposition 3.3 need not be true as shown in the following example.
Example 3.6
In example 3.1, the function f is **
X
FQ pre semi λ - continuous but not **
X
FQ regular -λ
continuous. Proposition 3.4
Let
(
X
1,
τ
*X1,Q*X*1) and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX is **X
FQ b -λ continuous then it is **
X
FQ pre semi-λ
continuous. Remark 3.4
The converse part of the above Proposition 3.4 need not be true as shown in the following example.
Example 3.7
Let X1=
{
a,b}
be a non empty set and*
1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , , , 1 , 0
{ 1 2 4 5
1
µ
µ
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3, 4, 5 1X
I ∈
µ
µ
µ
µ
µ
are defined as
µ
1(a)=0.4,µ
1(b)=0.3;µ
2(a)=0.4,µ
2(b)=0.1;µ
3(a)=0.8,, 3 . 0 ) ( ; 1 . 0 )
( 4
3 b =
µ
a =µ
µ
4(b)=0.3;µ
5(a)=0.3,µ
5(b)=0.1. Now, define :*
1 1
1 X
X X
Q →τ by
; )
( 1
1 a =µ
QX QX1(b)=µ3.Then, QX1 is a fuzzy scale and { 1, 3}.
*
1 = µ µ
X
Q Let ** {0,1, 1, 3}
1 = µ µ
X
Q be a
Let X2=
{
u,v}
be a non empty set and *2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4={0,1,ω3}be the fuzzy topologies on X2 where2
3 2 1, ,
X
I ∈
ω
ω
ω
defined as; 4 . 0 ) ( , 1 )
( 1
1 u =
ω
v =ω
ω
2(u)=0.4,ω
2(v)=0.3; ω3(u)=0.3, ω3(v)=0.3.
Now, define: *
2 2
2 X
X X
Q →τ by ( ) 1;
2 u =ω
QX QX2(v)=ω3.Then, QX2 is a fuzzy scale and { 1, 3}.
*
2 = ω ω
X
Q Let
} , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f :
(
X
1,
τ
*X1,Q*X*1)→ , )* * * 2
,
2 2(
X
τ
X QX be a fuzzy* *
X
FQ function defined by f(a) = u and f(b)
= v. Then the function ‘f’ is **
X
FQ pre semi-λcontinuous but not **
X
FQ b-λcontinuous.
Proposition 3.5
Let * , **)
1
,
1 1(
X
τ
X QX and * , **)2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f :
(
X
1,
τ
*X1,Q*X*1)→ , )* * * 2
,
2 2(
X
τ
X QX is* *
X
FQ t- continuous then it is **
X
FQ B -continuous.
Remark 3.5
The converse part of the above Proposition 3.5 need not be true as shown in the following example.
Example 3.8
In example 2.13, define the mapping f : * , **)
1
,
1 1(
X
τ
X QX → * , **)1
,
1 1(
X
τ
X QX by f(a) = a and f(b)= b. Then f is **
X
FQ B - continuous but not **
X
FQ t -continuous.
Proposition 3.6
Let
(
X
1,
τ
*X1,Q*X*1) and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX is **X
FQ regular -λ continuous then it is **
X
FQ t
-continuous.
Remark 3.6
The converse part of the above Proposition 3.6 need not be true as shown in the following example.
Example 3.9
Let X1=
{
a,b}
be a non empty set and *1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3 1X
I ∈
µ
µ
µ
are defined as; 2 . 0 ) ( , 6 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.7,µ
2(b)=0.2;µ
3(a)=0.1,µ
3(b)=0.8 . Now define: 1 * 1
1 X
X X
Q →τ by QX1(a)=µ2; QX1(b)=µ3.Then, QX1 is a fuzzy scale and { 2, 3}.
*
1 = µ µ
X
Q Let
} , , 1 , 0
{ 2 3
* *
1 = µ µ
X
Q be a fuzzy scalable structure on X1. Clearly, the triad
(
X
1,
τ
X*1,Q*X*1)is a fuzzyscalable structure space.
Let X2=
{
u,v}
be a non empty set and *2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4 ={0,1,ω3}be the fuzzy topologies on X2 where 1, 2, 3 2X
I ∈
ω
ω
ω
are definedas
ω
1(u)=0.2,ω
1(v)=0.8;ω
2(u)=0.2,ω
2(v)=0.3; ω3(u)=0.9,ω
3(v)=0.8.
Now, define: 2 * 2
2 X
X X
Q →τ by QX2(u)=
ω
1;QX2(v)=ω3.Then, QX2 is a fuzzy scale and { 1, 3}.*
2 = ω ω
X
Q Let
} , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f :
(
X
1,
τ
*X1,Q*X*1)→ , )* * * 2
,
2 2(
X
τ
X QX be a* *
X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ t - continuous but not **
X
FQ regular -λ
Proposition 3.7
Let * , **)
1
,
1 1(
X
τ
X QX and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : 1 * , **)
1 1
,
(
X
τ
X QX → , )* * * 2
,
2 2(
X
τ
X QX is* *
X
FQ regular -λ continuous then it is **
X
FQ b -λ
continuous. Remark 3.7
The converse part of the above Proposition 3.7 need not be true as shown in the following example.
Example 3.10
Let X1=
{
a,b}
be a non empty set and*
1 X
τ
be the collection of all fuzzy open sets in X1. Let} , , 1 , 0
{ 1 2
1
µ
µ
τ
= and τ2 ={0,1,µ3}be the fuzzy topologies on X1 where 1, 2, 3 1X
I ∈
µ
µ
µ
are defined as; 2 . 0 ) ( , 6 . 0 )
( 1
1 a =
µ
b =µ
µ
2(a)=0.7,µ
2(b)=0.2;µ
3(a)=0.1,µ
3(b)=0.8 . Now define: 1 * 1
1 X
X X
Q →τ by ( ) 2;
1 a =µ
QX QX1(b)=µ3.Then, QX1 is a fuzzy scale and { 2, 3}.
*
1 = µ µ
X
Q Let
} , , 1 , 0
{ 2 3
* *
1 = µ µ
X
Q be a fuzzy scalable structure on X1. Clearly, the triad
(
X
1,
τ
X*1,Q*X*1)is a fuzzyscalable structure space.
Let X2=
{
u,v}
be a non empty set and*
2 X
τ
be the collection of all fuzzy open sets in X2. Let} , , 1 , 0
{ 1 2
3
ω
ω
τ
= and τ4 ={0,1,ω3}be the fuzzy topologies on X2 where 1, 2, 3 2X
I ∈
ω
ω
ω
are definedas
ω
1(u)=0.3,ω
1(v)=0.8;ω
2(u)=0.2,ω
2(v)=0.3; ω3(u)=0.9,ω
3(v)=0.7.
Now, define: *
2 2
2 X
X X
Q →τ by ( ) 1;
2 u =
ω
QX ( ) 3.
2 v =ω
QX Then,
2
X
Q is a fuzzy scale and * { 1, 3}.
2 = ω ω
X
Q Let
} , , 1 , 0
{ 1 3
* *
2 = ω ω
X
Q be a fuzzy scalable structure on X2. Clearly, the triad
(
X
2,
τ
X*2,Q*X*2)is a fuzzyscalable structure space.
Let f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX be a **X
FQ continuous function defined by
f(a) = u and f(b) = v. Then the function ‘f’ is **
X
FQ b -λ continuous but not **
X
FQ regular -λ
continuous. Proposition 3.8
Let 1 * , **)
1 1
,
(
X
τ
X QX and , )* * * 2
,
2 2(
X
τ
X QX be any two fuzzy scalable structure spaces. If afunction f : * , **)
1
,
1 1(
X
τ
X QX → * , **)2
,
2 2(
X
τ
X QX is **X
FQ λ- continuous then it is **
X
FQ b -λcontinuous.
Remark 3.8
The converse part of the above Proposition 3.8 need not be true as shown in the following example.
Example 3.11
In example 3.10, the function f is **
X
FQ b -λcontinuous but not **
X
FQ λcontinuous.
Remark 3.9
From the above discussion we have the following implications are true:
Figure: 2 Relationship between **
X
FQ - pre semi
λ
continuity and other existing **X
FQ continuities *
*
X
FQ pre semi-λ
continuous *
*
X
FQ t-continuous
* *
X
FQ B -continuous
* *
X
FQ b-λcontinuous
* *
X
FQ – continuous
* *
X
FQ
λ
continuous* *
X
FQ regular- λ
Bibliography
[1] G. Balasubramanian and P. Sundaram, On some generalizations of fuzzy continuous, Fuzzy Sets and Systems, 86 (1997), 93-100.
[2] S. S. Benchalli and Jenifer J. Karnel, On fuzzy b-open sets in fuzzy topological spaces, J. Comp. & Math. Sci. 1 (2010), 127-134.
[3] A. S. Bin Shahna, On fuzzy strong continuity and fuzzy precontinuity, Fuzzy Sets and Systems, 44 (1991), 303-308. [4] M. Burgin, Discontinuity structures in topological spaces, International Journal of Pure and Applied Mathematics,
16(2004), 485 – 513.
[5] M. Burgin, Fuzzy Continuity in Scalable Topology, 2005.
[6] C. L. Chang, Fuzzy Topological Spaces, J. Math. Anal. Appl., 24(1968), 182-190.
[7] Miguel Caldas, Saeid Jafari, Govindappa Navalagi, More on Λ - closed sets in topological spaces , Revista Colombiana de Matematicas, 41 (2007), 355-369.
[8] S. Murugesan and P. Thangavelu , Fuzzy Pre-semi-closed Sets, Bull. Malays. Math. Sci. Soc. 31 (2008), 223–232. [9] S. S. Thakur and S. Singh, On fuzzy semi-preopen sets and fuzzy semipre-continuity, Fuzzy Sets and Systems,
98(1998), 383-391.
[10] M. K. Uma, E. Roja and G. Balasubramaniyan, A new characterization of fuzzy extremally disconnected spaces,