2. Graded Weakly 2-Absorbing Ideals
This section consists of an examination and studies of ‘GR-W-2-AI’. During the whole of this section, we are dealing with a ring R, that is an ‘NCGR-ring’, having unity except pointed out alternatively.
Definition 1. Let R be a ‘GR-ring’. Assume that P is a ‘PGR-I’ of R. Then we call P being a ‘GR-W-2-AI’ when gives , or for each . If implies , or for all , we call P to be ‘GR-CW-2-AI’.
Apparently, when R is a ‘CGR-rings’ having unity, then the concepts of ‘GR-W-2-A’ and ‘GR-CW-2-AI’ coincide. The following example demonstrates that this will not be the case for ‘NCGR-ring’.
Example 1. Consider (the ring of all matrices with integer entries) and . Then R is graded by , and .
Deal with ‘GR-I’ of R. P is Clearly a ‘GR-PI’ of R and so a ‘GR-W-2-AI’ of R. On the other side, P is not a ‘GR-CW-2-AI’ of R since , , and where , for each of , and .
Undoubtedly, every ‘GR-2-AI’ of a ‘GR-ring’ is a ‘GR-W-2-AI’. In any ‘GR-ring’, is ‘GR-W-2-AI’.
Individually, it is not necessary for to be ‘GR-2-AI’, check the next example.
Example 2. Suppose that along with . Hence R will be ‘GR-ring’ by , and . Undeniably, is not a ‘GR-2-AI’ of R since with but .
Lemma 1. For a ‘GR-ring’ R. Assume that P is a ‘GR-WPI’ of R.
- 1.
If for both I and J are graded right (left) ideals of R where, . Then it is either or .
- 2.
If such that , therefore each of x, y or .
Proof. Assume that both I and J are graded right (left) ideals of R in order that . Let and be the ‘GR-I’ generated by I and J respectively. Then , whence or .
Suppose that where . That being which it comes from (1) that or . By reiterating this, the result follows.
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Proposition 1. In the ‘GR-ring’ R. P is a ‘GR-W-2-AI’ of R, if it is a ‘GR-WPI’ of R.
Proof. Let where . By Lemma 1, or or . Accordingly, or or , and the result holds. □
Proposition 2. If P and K are two distinct ‘GR-WPI’ of a ‘GR-ring’ R, then is a ‘GR-W-2-AI’ of R.
Proof. Assume that , it seems that is a ‘GR-W-2-AI’ of R. Let where . Then and . By Lemma 1 we have and for some i and j, then . As a result, is a ‘GR-W-2-AI’ of R. □
Consider the two ‘GR-rings’ R and T. For all , is a graded by . is a ‘GR-I’ of if and only if P is a ‘GR-I’ of R and K is a ‘GR-I’ of T. The following example reveals that one can find ‘GR-W-2-AI’ which is not ‘GR-WPI’. Unfortunately, these rings that are used are commutative, indeed, we could not find such an example consisting of a non-commutative ring.
Example 3. Let , , and . Then and are the grades at that point of R. As well, T is a graded by and . In order that, is a graded by for all . Therefore, is a ‘GR-I’ of R and is a ‘GR-I’ of T as , so is a ‘GR-I’ of . Since with , and . Then P is not a ‘GR-WPI’ of . Individually, P is ‘GR-2-AI’ and hence a ‘GR-W-2-AI’ of .
Theorem 1. Let R be a ‘GR-ring’. Suppose that P is a ‘PGR-I’ of R. Assume that for graded left ideals and G of R such that , since , or . Then P is a ‘GR-W-2-AI’ of R.
Proof. Suppose that where . therefore, , and as a consequence, since R has a unity, . By assumption, we have or or . Accordingly, P will be ‘GR-W-2-AI’. □
Theorem 2. Theorem 1 still true if graded left ideals are replaced by graded right ideals.
Let R be a ‘GR-ring’ and K is a ‘GR-I’ of R, then is a graded by for any . For P as an ideal of R and K is a ‘GR-I’ of R such that , then P is a ‘GR-I’ of R if and only if is a ‘GR-I’ of .
Proposition 3. For a graded ring R. Assume that P is a ‘GR-W-2-AI’ of R. Let , if K is a ‘GR-I’ of R, then is a ‘GR-W-2-AI’ of .
Proof. Let with . Hence with . Because P is ‘GR-W-2-AI’, for , or , therefore, or or . So, is a ‘GR-W-2-AI’ of . □
Proposition 4. For a graded ring R. Let is a ‘PGR-I’ of a ‘GR-ring’ R. Then P is a ‘GR-W-2-AI’ of R, if K is a ‘GR-W-2-AI’ of R and is a ‘GR-W-2-AI’ of .
Proof. Suppose that with . Therefore, such that . If , then or or since K is a ‘GR-W-2-AI’ of R. If , then . Since is a ‘GR-W-2-AI’ of , or or , that yields that , or . Therefore, P is a ‘GR-W-2-AI’ of R. □
For two ‘GR-rings’ S and T. We call to be graded homomorphism f is ring homomorphism and for every .
Proposition 5. Let S and T be two ‘GR-rings’ and be graded homomorphism. Then is a ‘GR-I’ of S.
Proof. Apparently, is an ideal of S. Assume that . Hence such that . Now, , with for all , which lead to for all . As a result, for , with , which yields that for all along with is a ‘GR-I’. Therefore, for any , and then is a ‘GR-I’ of S. □
Theorem 3. For the two ‘GR-rings’ S and T and be surjective graded homomorphism.
- 1.
will be a ‘GR-W-2-AI’ of T, if P is a ‘GR-W-2-AI’ of S and .
- 2.
will be a ‘GR-W-2-AI’ of S, if I is a ‘GR-W-2-AI’ of T and is a ‘GR-W-2-AI’ of R.
Proof. Let be a ‘GR-I’ of T. Because P is a ‘GR-W-2-AI’ of R and , Proposition 3 shows that is a ‘GR-W-2-AI’ of . The result holds Since is isomorphic to T.
Assume that is a ‘GR-I’ of S. Let . Then . We observe that is a ‘GW-2-AI’ of , since is isomorphic to T. Because is a ‘GR-W-2-AI’ of S and is a ‘GR-W-2-AI’ of , Proposition 4 states that is a ‘GR-W-2-AI’ of S.
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Motivated by Theorem 1, we observe the next question.
Question 1. IfPis a ‘GR-W-2-AI’ ofRthat is not a ‘GR-2-AI’ andfor some ‘GR-I’E,FandKofR. Does it indicate thatoror?
We will give a partial answer through the coming discussions. Motivated by ([
4], Definition 3.3), we introduce the following:
Definition 2. Assume that R is a ‘GR-ring’, and P is a ‘GR-I’ of R with .
- 1.
If for each where , then P is said to be a ‘GR-2-AI’ of R, therefore, , or .
- 2.
If for each where , then P is said to be a ‘GR-W-2-AI’ of R, therefore, , or .
- 3.
For , let P is a ‘GR-W-2-AI’ of R and. We denote ‘GR-3-Z’ for which is the graded-triple-zero of P if , such that , and .
Note that if P is ‘GR-W-2-AI’ which is not ‘GR-2-AI’, then P involves a ‘GR-3-Z’ for .
Proposition 6. Assume that for any and some graded left ideal K of R, and that P is a ‘GR-W-2-AI’ of R. Let is not a ‘GR-3-z’ of P for every . If , then or .
Proof. Consider that along with . Then there exist such that and . Since and since is not a GR-3-Z of P and , , we obtain that . Also, since and since is not a GR-3-Z of P and , , we obtain that . Now, since and since is not a GR-3-Z of P and , we get or . If , then since , , a contradiction. If , then since , , a contradiction. Hence, or . □
Definition 3. Let R be a ‘GR-ring’ and P be a ‘GR-W-2-AI’ of R. Assume that for some ‘GR-I’ and K of R. If is not a ‘GR-3-Z’ of P for every and . We can state P as being a free ‘GR-3-Z’ respecting . The next proposition is clear.
Proposition 7. Let P is a ‘GR-W-2-AI’ of R. Presume that and P to be a free ‘GR-3-Z’ in respect to , for some ‘GR-I’ and K of R. If and , then , or .
Theorem 4. Infer that P is a ‘GR-W-2-AI’ of R. Lets take and P to be a free ‘GR-3-Z’ in respect to , for some ‘GR-I’ and K of R. Then , or .
Proof. Suppose that , and . There exist and where and . Now, . Since and , it comes from Proposition 6 that . Because , there are and where . Since and , it comes from Proposition 6 that or .
Case (1): and . Since and and , it follows from Proposition 6 that . Since and , we obtain that . On the other hand, since and neither nor , we have that by Proposition 6, and hence , which is not true.
Case (2): and . Using an analogous assertion to case (1), we will have an inconsistency.
Case (3): and . Since and , . But and neither nor , and hence by Proposition 6. Since and , we have that . Since and neither nor , we conclude that by Proposition 6, and hence . Since and neither nor , we have by Proposition 6. But , so , a contradiction. Consequently, or or . □
Lemma 2. For a ‘GR-ring’ R. Assume that P is a ‘GR-W-2-AI’ and is a ‘GR-3-Z’ of P for some . Then
- 1.
,
- 2.
,
- 3.
,
- 4.
,
- 5.
,
- 6.
.
Proof. Assume that . Then there exist and such that . Now, . Hence, . We have or , since P is ‘GR-W-2-AI’. Thus or is a contradiction.
Suppose that . Then there exist and such that . Now, . Hence, . If P is ‘GR-W-2-AI’ We have or . As a result, or is a contradiction.
Suppose that . However, there exists for which . Now, . Hence, . We have or . Because P is ‘GR-W-2-AI’. Hence, or is a contradiction.
Suppose that . Moreover, there exist in which . Now, by (2) and (3). Hence, . We have or or . Because P is ‘GR-W-2-AI’. Hence, or or is a contradiction.
Suppose that . Moreover, there exist , where, . Now, by (1) and (3), . As a result, . We have , or . Because, P is ‘GR-W-2-AI’. Hence, , or is a contradiction.
Suppose that . Then there exist such that . Now, by (1) and (2), . Hence, . We have or or . Because P is ‘GR-W-2-AI’. As a result, , or is a contradiction.
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The following theorem is a consequence result from Lemma 2.
Theorem 5. Let R be a ‘GR-ring’, and P be a ‘GR-I’ of R such that . Then P is ‘GR-W-2-AI’ if and only if P is ‘GR-2-AI’.
Proof. Assume that P is a ‘GR-W-2-AI’ that is not the same as a ‘GR-2-AI’ of R. For some . Let P has a ‘GR-3-Z’, say . Therefore, if , there exist where , and then . As a result, . We have either , or . Because P is ‘GR-W-2-AI’, and thus either , or which is a contradiction. Hence, P is a ‘GR-2-AI’ of R. The contrary is self-evident. □
Corollary 1. Assume R to be a ‘GR-ring’. If P is a ‘GR-W-2-AI’ of R and it is not ‘GR-2-AI’, then .
Allow to be a ‘GR-ring’ and M to be an R-module. Then M is considered to be a graded if for any , with , where is an additive subgroup of M. The components of are known as homogeneous of degree g.
For any It is obvious that is an -submodule of M. The set of all homogeneous components of M is and is denoted by . Let N be an R-submodule which is a graded R-module M, and denoted by ‘GR-R’-submodule.
If , or equivalently, , i.e., for any . Then N is said to be graded R-submodule.
It is well known that an
R-submodule of a ‘GR-
R’-module does not need to be graded. For more terminology see [
2,
3].
Assume
M to be an
-
R-module. The idealization (trivial extension)
of
M is a ring with component wise addition defined by:
and multiplication is defined by:
for each
and
. Let
G be an Abelian group and
M be a ‘GR-R’-module. Then for any
,
is a graded by
[
9].
Theorem 6. Let R be a GR-ring with unity, M be a GR--R-module and P be a ‘P-GR-I’ of R. Hence, is a ‘GR-2-AI’ of if and only if P is a ‘GR-2-AI’ of R.
Proof. For some . Assume that is a ‘GR-2-AI’ of and . Then with , and then , or . A a result, , or , as required. In the opposite case, let for some . Therefore, with , we obtain , or . If true, then . Similarly, if , then , and if , then , and so on, this completes the proof. □
Theorem 7. Let R be a ‘GR-ring’ with unity, M to be a ‘GR-bi-R’-module and P to be a ‘PGR-I’ of R. If is a ‘GR-W-2-AI’ of , then P is a ‘GR-W-2-AI’ of R.
Proof. For , let . Then , and then , or . As a result, , or . So, P is ‘GR-W-2-AI’. □
Theorem 8. Let R be a ‘GR-ring’ with unity, M be a ‘GR-bi-R’-module, and P to be a ‘GR-I’ of R with . Hence is a ‘GR-W-2-AI’ of if and only if P is a ‘GR-W-2-AI’ of R and for every ‘GR-3-Z’, of P we got .
Proof. Assume that is a ‘GR-W-2-AI’ of . Let , with . Then , and then or or . As a result, , or . So, P is ‘GR-W-2-AI’. Preduse that is a ‘GR-3-Z’ of P. Assume that . Hence there exist and such that , and then . However, and and , which contradicting the statement that is a ‘GR-W-2-AI’. If , hence, there exist and such that . As above, we have . however, there is a contradiction between , and . If , then there exists where, . At the present, . However, there is a contradiction between and and . Conversely, suppose that for . Then with .
Case (1):. Since P is GR-W-2-AI, it might be , or . Hence, , or , as desired.
Case (2):. If , and , then is a ‘GR-3-Z’ of P and by assumption . Now, , a contradiction. □
Question 2. As a proposal for future work, we think it will be worthy to study non-commutative graded rings such that every ‘GR-I’ is ‘GR-W-2-AI’. What kind of results will be achieved?
The following abbreviations are used throw this Article: ‘GR-SW-2-AI’ for the graded strongly weakly 2-absorbing ideals.
On the other hand, we present the idea of ‘GR-SW-2-AI’, and examine ‘GR-rings’ in which every ‘GR-I’ is ‘GR-SW-2-AI’.
Definition 4. Let R be a ‘GR-ring’ and P to be a ‘PGR-I’ of R. If and C are ‘GR-I’ of R where . So, , or . Then P is said to be a ‘GR-SW-2-AI’ of R.
Proposition 8. Let P be a ‘PGR-I’ of R. Then P is a ‘GR-SW-2-AI’ of R if and only if for any ‘GR-I’ and C of R such that (or or ), implies that , or .
Proof. The result holds by the above definition If P is a ‘GR-SW-2-AI’ of R. Conversely, let and C be ‘GR-I’ of R where, . Hence is a GR-I of R such that , and then by assumption, or or . As a result, , or . Hence, P becomes a ‘GR-SW-2-AI’ of R. □
Proposition 9. Let R be a ‘GR-ring’. Then every ‘GR-I’ of R is ‘GR-SW-2-AI’ if and only if for any ‘GR-I’ and K of R, , , or .
Proof. Suppose that every ‘GR-I’ of R is ‘GR-SW-2-AI’. Let and K be ‘GR-I’ of R. If , then is ‘GR-SW-2-AI’. Suppose that . Then and , or and hence , or . If , then . Conversely, let P be a PGR-I of R, for some ‘GR-I’ and K of R. Then or or . Hence, P is a ‘GR-SW-2-AI’ of R. □
Corollary 2. Assume R to be a ‘GR-ring’ where every ‘GR-I’ of R is ‘GR-SW-2-AI’. Then or for every ‘GR-I’ of R.