American Journal of Mathematics and Statistics
p-ISSN: 2162-948X e-ISSN: 2162-8475
2020; 10(2): 33-37
doi:10.5923/j.ajms.20201002.01

Osama Rashad El-Gendy
Batterjee Medical College for Sciences & Technology, Jeddah, Saudi Arabia
Correspondence to: Osama Rashad El-Gendy, Batterjee Medical College for Sciences & Technology, Jeddah, Saudi Arabia.
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Copyright © 2020 The Author(s). Published by Scientific & Academic Publishing.
This work is licensed under the Creative Commons Attribution International License (CC BY).
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In this paper, the concept of bipolar fuzzy α-ideal of BP-algebra is introduced. We introduced α-ideal and fuzzy α-ideal. Several theorems are presented in this regard. The homomorphic image and inverse image of the bipolar fuzzy α-ideal are studied.
Keywords: BP-algebra, α-ideal, fuzzy α-ideal, Bipolar fuzzy -ideal
Cite this paper: Osama Rashad El-Gendy, Bipolar Fuzzy α-ideal of BP-algebra, American Journal of Mathematics and Statistics, Vol. 10 No. 2, 2020, pp. 33-37. doi: 10.5923/j.ajms.20201002.01.
is called BP-algebra if it satisfies the following axioms:
In X, we can define a binary relation “≤” by x ≤ y if and only if
Example 2.2 [2]. Let
. Define
on
as the following table:
Then
is a BP-algebra.Theorem 2.3 [2]. If
is a BP-algebra, then following conditions hold: for any 
Example 2.4 [2]. Let
Define
as the following table:
Then
is a BP-algebra
and fuzzy
of BP-algebra are defined and some important properties are presented.Definition 3.1. A nonempty subset S of a BP-algebra X is called a subalgebra of X if
for all
Definition 3.2. A non-empty subset
of a BP-algebra
is called a
if for all 
Definition 3.3. Let
and
be BP-algebra. A mapping
is said to be a homomorphism if
, for all
Definition 3.4. Let
be a BP-algebra. A fuzzy set
is called a fuzzy
if it satisfies:
Example 3.5. Consider a BP-algebra X = {0, a, b, c} in which the
operation is given by example 2.4. Let 
be such that
. Define the mapping
by
,
and
Then routine calculations give that
is a fuzzy
of X.Proposition 3.6. If
is a fuzzy α-ideal of BP-algebra X, then
implies
, for all
.Proof. Let
be a Fuzzy
of BP-algebra X.By definition 2.1, if
then
and
given that
for all
Then 
of BP-algebra and examined some related properties.Definition 4.1 [22]. A bipolar fuzzy set
is defined as
where 
and
are mappings. The positive membership degree
denotes the satisfaction degree of an element
to the property corresponding to a bipolar fuzzy set
and the negative membership degree
denotes the satisfaction degree of an element
to some implicit counter property of
If
and
this case is regarded as having only a positive satisfaction degree for
If
and
does not satisfy the property of 
but somewhat satisfies the counter property of
In some cases, it is possible for an element
to be
and
when the membership function of the property overlaps that of the counter property of its portion of the domain (Lee [26]). We shall use the symbol
for the bipolar fuzzy set
Definition 4.2 [32]. For every two bipolar fuzzy set
and
in
we define 
Proposition 4.3 [21]. A bipolar fuzzy set
of
is called a bipolar fuzzy subalgebra of
if it satisfies
and
for all
Definition 4.4 [21]. A bipolar fuzzy set
of
is called a bipolar fuzzy ideal of
if it satisfies the following conditions
Definition 4.5. A bipolar fuzzy set
of a BP-algebra
is called a bipolar fuzzy
of
if it satisfies the following conditions
Example 4.6. Consider a BP-algebra X = {0, a, b, c} in which the
operation is given by example 2.4. Define a bipolar fuzzy set
by,
and
routine calculation gives that
is a bipolar fuzzy
of
.Theorem 4.7. The intersection of any set of bipolar fuzzy
in BP-algebra
is also a bipolar fuzzy
of
. Proof. Let
be a family of bipolar fuzzy
in BP-algebra
. Then for any 
And 
Proposition 4.8. Let
be a bipolar fuzzy
of BP-algebra. If
holds in
, then
and
Proof. Let
holds in
. Then
Since
and
Then 
And 
Proposition 4.9. Let
be a bipolar fuzzy
of BP-algebra
. If
holds in
, then
and
Proof. Let
holds in
. Then
Since
Then 
And
Then 
Definition 4.10. Let
be a bipolar fuzzy
of BP-algebra
and
We define
is called upper
cut of
and lower
cut of
of the bipolar fuzzy
Theorem 4.11. Let
be a bipolar fuzzy
of BP-algebra
. Then for every 
is
of BP-algebra.Proof. Assume that
is a bipolar fuzzy
of
. For
so
and
where
Now we get that
and
this implies that
Next, let
This means
and
also,
and
Then
and
This implies that
Hence
is a
of BP-algebra.Definition 4.12. Let
and
be BP-algebras, and let
be a mapping from the set
and the set
. If
and
are bipolar fuzzy sets of
and
respectively. Then
And
For all
is called the image of
under
. Similarly, the inverse image
in
defined as,
and
for all
Theorem 4.13. An into homomorphic inverse image of a bipolar fuzzy
of BP-algebra is also bipolar fuzzy
Proof. Let
be an into homomorphism of BP-algebras. Assume that
is a bipolar fuzzy
in
, and
is a bipolar fuzzy
in
. Then for all 
and
Now, let
Then
And,
Hence the inverse image of a bipolar fuzzy
of BP-algebra is also bipolar fuzzy
Definition 4.14. A bipolar fuzzy subset
has
and
properties if for any subset
there exist
such that
and
Theorem 4.15. An onto homomorphic image of a bipolar fuzzy
of BP-algebra with
and
properties is a bipolar fuzzy
Proof. Let
be an onto homomorphism of BP-algebras and
is a bipolar fuzzy
in
. Let
is a bipolar fuzzy
in
with
and
properties. Then for all
we get
and
Since
is a bipolar fuzzy
in
. We have
and
Note that
such that and are the zero elements of
and
respectively. Thus
and 
This implies that
and
for all
For any
let 
be such that
and
and
Then
Similarly, we have
and
and 
Then
Hence the onto homomorphic image of a bipolar fuzzy
of BP-algebra is also bipolar fuzzy 
with special properties plays an important role. In the present paper, we have applied the notion of the bipolar fuzzy set theory to
of BP-algebra and investigated some of their useful properties. In the future, these definitions and fundamental results can be applied to some different algebraic structures. There are more topics that could take advantage of
. Like for example cubic intuitionistic
of BP-algebra, cubic fuzzy
of BP-algebra, and fuzzy soft
in BP-algebra. There are many other aspects which should be explored and studied in the area of BP-algebra such as anti-fuzzy
of BP-algebra, interval-valued fuzzy
of BP-algebra, intuitionistic fuzzy
of BP-algebra, doubt intuitionistic fuzzy
of BP-algebra, fuzzy derivations
of BP-algebra, and interval-valued intuitionistic fuzzy
of BP-algebra. It is our hope that this work would other foundations for further study of the theory of BP-algebra.