Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 284 https://internationalpubls.com On Soft Strongly ฦ„โˆ— โˆ’ ๐‚๐ฅ๐จ๐ฌ๐ž๐ Via Soft Ideal Abdelaziz E. Radwan1, Essam El-Seidy2, Saif Z. Hameed*, 3 1, 2Department of Mathematics, Faculty of Science, Ain Shams University, Cairo, Egypt 3Department of Mathematics, College of Education, Mustansiriyah University, Baghdad, Iraq Email address: 1zezoradwan@yahoo.com, 2esam_elsedy@hotmail.com, 3saif.zuhar.edbs@uomustansiriyah.edu.iq 3https://orcid.org/0000-0001-6197-3525 Article History: Received: 01-02-2024 Revised: 15-04-2024 Accepted: 04-05-2024 Abstract: In this paper, we introduce the soft strongly ฦ„โˆ— โˆ’closed via soft ideal and study the behavior of intersection and union of this level. Also, we define the soft strongly ฦ„โˆ—แฟ˜ โˆ’continuous, irresolute, soft strongly ฦ„โˆ—แฟ˜ โˆ’open map and soft strongly ฦ„โˆ—แฟ˜ โˆ’closed map with some properties. Moreover, the relationship between another closed sets and soft strongly ฦ„โˆ—แฟ˜ โˆ’closed with counterexamples are discuss. Keywords: soft ideal, ๐‘ ๐‘†ฦ„โˆ— โˆ’closed set, ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed, ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’continuous, ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’irresolute. Mathematics Subject Classification: 54A05, 54A10, 54A20, 54A40. 1. Introduction and Preliminaries Molodtsov [1], instigated the concept of soft set as a new mathematical tool to deal with uncertainties problems in different fields of science. I. Arockiarani and A. Arokialancy [2] studied the soft ๐›ฝ โˆ’open sets and continuous. Akdag and Ozkan [3, 4] introduced the soft ๐›ผ-open and define soft b-open and continuous. Hameed, S. Z., Hussein, A. K [5] defined the soft ฦ„๐‘ โˆ’open set. The soft ฦ„โˆ— โˆ’ closed, ๐‘ ฦ„โˆ— โˆ’continuous, ๐‘ ๐‘†ฦ„โˆ— โˆ’closed sets and ๐‘ ๐‘†ฦ„โˆ— โˆ’continuous functions are studied by Saif at el. in [6], [7] and [8]. Kandil et al. [9] define soft ideal and introduced the soft local function. These concepts are discussed with a view to find new soft topologies from the original one, called ๐’ฎTSs with soft ideal (๐’ต, ๐”š, ๐›ฅ, แฟ˜). Mustafa and Sleim [10] studied the notion of a soft ideal and they introduced the soft generalized closed sets with respect to a soft ideal and studied their properties in detail, which is extension of the concept of soft generalized closed sets. Later, K. Kannan [11] introduced the soft g-closed soft sets in a ๐’ฎTS. In this work, we study the concept of ๐‘ ๐‘†ฦ„โˆ— โˆ’closed set via soft ideal, Also, we study the relationship between ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed sets and other existing soft sets have been investigated. Moreover, the ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’continuous, irresolute, ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’open map and ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed map with counterexamples are discuss. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 285 https://internationalpubls.com Definition 1.1: [1] Let ๐’ต be an initial universe set and ๐ธ be a set of parameters. Let ๐‘ƒ(๐’ต) denote the power set of ๐’ต, and โˆ†โŠ‚ ๐ธ. A pair (๐›พ, ๐›ฅ) is called a soft set over ๐’ต. Where ๐›พ is a mapping given by ๐›พ: ๐›ฅ โ†’ ๐‘ƒ(๐’ต). The family of all soft sets over ๐’ต denote by ๐‘†๐‘†(๐’ต, ๐›ฅ) Definition 1.2: [12] The soft set (๐›ฟ, ๐›ฅ) โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ), where ๐›ฟ(๐‘) = โˆ…, for every c โˆˆ ๐›ฅ is called A-null soft set of ๐‘†๐‘†(๐’ต, ๐›ฅ) and denoted by โˆ…ฬƒ. The soft set (๐›ฟ, ๐›ฅ) โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ), where ๐›ฟ(๐‘) = ๐’ต, for every ๐‘ โˆˆ ๐›ฅ is called the A-absolute soft set of ๐‘†๐‘†(๐’ต, ๐›ฅ) and denoted by ๐’ต. Definition 1.3: [12] For two sets (๐›พ, ๐›ฅ), (๐›ฟ, ๐ต) โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ), we say that (๐›พ, ๐›ฅ) is a soft subset of (๐›ฟ, ๐ต) denoted by (๐›พ, ๐›ฅ) โІ (๐›ฟ, ๐ต), if (1) ๐›ฅ โІ ๐ต. (2) ๐›พ(๐›ป) โІ ๐›ฟ(๐›ป), โˆ€ ๐›ป โˆˆ ๐›ฅ. In this case, (๐›พ, ๐›ฅ) is said to be a soft superset of (๐›ฟ, ๐ต), if (๐›ฟ, ๐ต) is a soft subset of (๐›พ, ๐›ฅ), (๐›พ, ๐›ฅ) โЇ (๐›ฟ, ๐ต). Definition 1.4: [13] Let (๐›พ, ๐›ฅ) be a soft set over ๐’ต and ๐‘ง โˆˆ ๐’ต. We say that ๐‘ง โˆˆ (๐›พ, ๐›ฅ) read as ๐‘ง belongs to the soft set (๐›พ, ๐›ฅ) whenever ๐‘ง โˆˆ ๐›พ (โˆ‡) for all ๐›ป โˆˆ ๐›ฅ. The soft set (๐›พ, ๐›ฅ) over ๐’ต such that ๐›พ (๐›ป) = { ๐‘ง } โˆ€ โˆ‡ โˆˆ ๐›ฅ is called singleton soft point and denoted by ๐‘ง๐›ฅ or (๐‘ง, ๐›ฅ). Definition 1.5: [13] Let ๐”š be a collection of soft sets over ๐’ต, then ๐”š is said to be ๐’ฎTS on ๐’ต if (1) โˆ…ฬƒ and ๐’ต belong to ๐”š. (2) The union of any subcollection of soft sets of ๐”š belongs to ๐”š. (3) The intersection of any two soft sets in ๐”š belongs to ๐”š. It is denoted by ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) and briefly ๐’ต. Definition 1.6: [13] Let (๐’ต, ๐”š, ๐›ฅ) be a soft space over ๐’ต, then the members of ๐”š are said to be soft open sets in ๐”š. Definition 1.7: [13] Let (๐’ต, ๐”š, ๐›ฅ) be a soft space over ๐’ต. A soft set (P, ๐›ฅ) over ๐’ต is said to be a soft closed set in ๐’ต, if its relative complement (๐›พ, ๐›ฅ)โ€ฒ belongs to ๐”š. Definition 1.8: [14] Let (๐’ต, ๐”š, ๐›ฅ) be a ๐’ฎTS and (๐›พ, ๐›ฅ) โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ). Then (1) The soft closure of (๐›พ, ๐›ฅ) is the soft set ๐‘๐‘™(๐›พ, ๐›ฅ) = โˆฉ {(๐ฟ, ๐›ฅ) โˆถ (๐ฟ, ๐›ฅ) โˆˆ ๐”š๐‘ , (๐›พ, ๐›ฅ) โІ (๐ฟ, ๐›ฅ)}. (2) The soft interior of (๐›พ, ๐›ฅ) is the soft set ๐‘–๐‘›๐‘ก(๐›พ, ๐›ฅ) = โˆช {(๐ป, ๐›ฅ) โˆถ (๐ป, ๐›ฅ) โˆˆ ๐”š, (๐ป, ๐›ฅ) โІ (๐›พ, ๐›ฅ)}. Definition 1.9: [4, 5, 7, 19] A soft set (๐›ฟ, ๐›ฅ) of a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) is said to be (1) soft ฮฑ- open if (๐›ฟ, ๐›ฅ) โŠ‚ ๐‘–๐‘›๐‘ก(๐‘๐‘™(๐‘–๐‘›๐‘ก((๐›ฟ, ๐›ฅ)))). (2) soft preopen if (๐›ฟ, ๐›ฅ) โŠ‚ ๐‘–๐‘›๐‘ก(๐‘๐‘™((๐›ฟ, ๐›ฅ))). Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 286 https://internationalpubls.com (3) soft semi - open if (๐›ฟ, ๐›ฅ) โŠ‚ ๐‘๐‘™(๐‘–๐‘›๐‘ก((๐›ฟ, ๐›ฅ))). (4) soft ฮฒ-open if (๐›ฟ, ๐›ฅ) โŠ‚ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐‘๐‘™((๐›ฟ, ๐›ฅ)))). (5) soft ฦ„ โˆ’open if (๐›ฟ, ๐›ฅ) โŠ‚ ๐‘–๐‘›๐‘ก(๐‘๐‘™((๐›ฟ, ๐›ฅ))) โˆช ๐‘๐‘™(๐‘–๐‘›๐‘ก((๐›ฟ, ๐›ฅ)))). Definition 1.15: [8] A soft set (๐›พ, ๐›ฅ) of a ๐’ฎTS(๐’ต, ๐”š, ๐›ฅ) is called a soft strongly ฦ„โˆ— โˆ’closed (briefly s๐‘†ฦ„โˆ— โˆ’closed) if ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ๐›ฅ)) โІ (๐›ฟ, ๐›ฅ), whenever (๐›พ, ๐›ฅ) โŠ‚ (๐›ฟ, ๐›ฅ) and (๐›ฟ, ๐›ฅ) is soft ฦ„ โˆ’open. The complement of a ฦ„โˆ— ฦ„โˆ— โˆ’closed set is called ฦ„โˆ— ฦ„โˆ— โˆ’open set. The family of all ฦ„โˆ— ฦ„โˆ— โˆ’open sets denoted by ๐‘ ๐‘†ฦ„โˆ—๐‘‚๐‘†(๐’ต). Theorem 1.16: [8] The following statements are true. (i) Every soft open is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. (ii) Every ๐‘ ๐›ผ โˆ’open is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. (iii) Every ๐‘ ๐‘†ฦ„โˆ— โˆ’open set is ๐‘ ฦ„ โˆ’open. (iv) Every ๐‘ ๐œ” โˆ’open is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Definition 1.17: [9] Let แฟ˜ be a non-null collection of soft sets over a universe ๐’ต with the same set of parameters โˆ†. Then, แฟ˜ โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ) is called a soft ideal on ๐’ต with the same set โˆ† if (1) (๐›พ, ๐›ฅ) โˆˆ แฟ˜ and (๐›ฟ, ๐›ฅ) โˆˆ แฟ˜ โ‡’ (๐›พ, ๐›ฅ) โˆช (๐›ฟ, ๐›ฅ) โˆˆ แฟ˜, (2) (๐›พ, ๐›ฅ) โˆˆ แฟ˜ and (๐›ฟ, ๐›ฅ) โІ (๐›พ, ๐›ฅ) โ‡’ (๐›ฟ, ๐›ฅ) โˆˆ แฟ˜. i.e., แฟ˜ is closed under finite soft unions and soft subsets. Definition 1.18: [10] A soft set (๐›พ, ๐›ฅ) โˆˆ ๐‘†๐‘†(๐’ต, ๐›ฅ) is called soft generalized closed set with respect to soft ideal แฟ˜ (soft แฟ˜g โˆ’closed set) in ๐’ฎTS(๐’ต, ๐”š, ๐›ฅ) if ๐‘๐‘™(๐›พ, ๐›ฅ)\(๐›ฟ, ๐›ฅ) โˆˆ แฟ˜ whenever (๐›พ, ๐›ฅ) โŠ‚ (๐›ฟ, ๐›ฅ) and (๐›ฟ, ๐›ฅ) โˆˆ ๐”š. 2. SS ฦ„โˆ— โˆ’closed via soft ideal In this section, we define ๐‘ ๐‘†ฦ„โˆ— โˆ’closed set via soft ideal and study some of their properties. Definition 2.1: A soft set (๐›พ, ฮ”) of a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) is called a soft strongly ฦ„โˆ— โˆ’closed with respect to soft ideal แฟ˜ (briefly s๐‘†ฦ„โˆ—แฟ˜ โˆ’closed) if ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ๐›ฅ)) \ (๐›ฟ, ๐›ฅ) โˆˆ แฟ˜, whenever (๐›พ, ๐›ฅ) โŠ‚ (๐›ฟ, ๐›ฅ) and (๐›ฟ, ๐›ฅ) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Example 2.2. Let ๐’ต = {ํœ€, ๐œ‡} and โˆ†= {โˆ‡1, โˆ‡2} . Let (๐›พ1, ฮ”), (๐›พ2, ฮ”) and (๐›พ3, ฮ”) be three soft sets, where (๐›พ1, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {ํœ€})}, (๐›พ2, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, โˆ…)} and (๐›พ3, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, {ํœ€})}. Then (๐›พ1, ฮ”), (๐›พ2, ฮ”) and (๐›พ3, ฮ”) are soft sets over ๐’ต and ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ1, ฮ”), (๐›พ2, ฮ”), (๐›พ3, ฮ”)} is the soft topology over ๐’ต. Let แฟ˜ = {โˆ…ฬƒ, (๐›ฟ1, ฮ”), (๐›ฟ2, ฮ”), (๐›ฟ3, ฮ”)} be a soft ideal on ๐’ต, where (๐›ฟ1, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, โˆ…)}, Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 287 https://internationalpubls.com (๐›ฟ2, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, {ํœ€})} and (๐›ฟ3, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {ํœ€})}. The soft sets (๐œ—1, ฮ”), (๐œ—2, ฮ”), (๐œ—3, ฮ”) are ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed, where (๐œ—1, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, ๐’ต)}, (๐œ—2, ฮ”) = {(โˆ‡1, ๐’ต), (โˆ‡2, {ํœ€})} and (๐œ—3, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, {๐œ‡})}. And we see the soft set (๐œ‰, ฮ”) is not ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed, where (๐œ‰, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {ํœ€})}. Theorem 2.3: (1) Every soft g โˆ’closed set is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. (2) Every closed soft set is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. (3) Every soft แฟ˜g โˆ’closed set is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. Proof. (1) Let (๐›พ, ฮ”) โІ (๐›ฟ, ฮ”) and (๐›ฟ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Since (๐›พ, ฮ”) is soft g โˆ’closed โ‡’ ๐‘๐‘™(๐›พ, ฮ”) โІ (๐›ฟ, ฮ”) and ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) โІ ๐‘๐‘™(๐›พ, ฮ”). So, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐›ฟ, ฮ”) = โˆ… โˆˆ แฟ˜. Therefore, (๐›พ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. (2) Let (๐›พ, ฮ”) โІ (๐›ฟ, ฮ”) and (๐›ฟ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Since (๐›พ, ฮ”) is soft closed, then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) โІ ๐‘๐‘™(๐›พ, ฮ”) = (๐›พ, ฮ”) โІ (๐›ฟ, ฮ”). Hence, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐›ฟ, ฮ”) = โˆ… โˆˆ แฟ˜. Therefore, (๐›พ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. (3) Let (๐›พ, ฮ”) โІ (๐œ‰, ฮ”) and (๐œ‰, ฮ”) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐œ‰, ฮ”) โІ ๐‘๐‘™(๐›พ, ฮ”)\(๐œ‰, ฮ”) โˆˆ แฟ˜, (๐œ‰, ฮ”) โˆˆ แฟ˜ Hence, (๐›พ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. The converse of the above theorem is not true in general. The following examples support our claim. Example 2.4: Let ๐’ต = {ํœ€, ๐œ‡} . Let โˆ†= {โˆ‡1, โˆ‡2}. Let (๐›พ1, ฮ”), (๐›พ2, ฮ”), (๐›พ3, ฮ”) and (๐›พ4, ฮ”) be four soft sets, where (๐›พ1, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, ๐’ต)}, (๐›พ2, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, โˆ…)}, (๐›พ3, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, {๐œ‡})} and (๐›พ4, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, {ํœ€})}. Then, ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ1, ฮ”), (๐›พ2, ฮ”), (๐›พ3, ฮ”), (๐›พ4, ฮ”)} is the soft topology over ๐’ต. Let แฟ˜ = {โˆ…ฬƒ, (๐›ฟ1, ฮ”), (๐›ฟ2, ฮ”), (๐›ฟ3, ฮ”)} be a soft ideal on ๐’ต, where (๐›ฟ1, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, โˆ…)}, (๐›ฟ2, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, {ํœ€})} and (๐›ฟ3, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {ํœ€})}. The soft sets (๐œ—, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed but not soft g โˆ’closed, where (๐œ—, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {๐œ‡})}. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 288 https://internationalpubls.com Example 2.5: In Example 2.2, the soft set (ฮ“, ฮ”) = {(โˆ‡1, ๐’ต), (โˆ‡2, {ํœ€})} is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed but not closed soft se. Example 2.6: In Example 2.4, the soft set (ฮถ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed but not soft แฟ˜g โˆ’closed set, where (ฮถ, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {๐œ‡})}. Remark 2.7: If a soft subset (๐›พ, ฮ”) of a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) is soft open, then it is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed if and only if it is soft แฟ˜g โˆ’closed. Theorem 2.8: A soft set (๐œ—, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) if and only if (๐›พ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”) and (๐›พ, ฮ”) is soft closed implies (๐›พ, ฮ”) โˆˆ แฟ˜. Proof. (โ‡’) Let (๐›พ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”) and (๐›พ, ฮ”) is soft closed. Then, (๐œ—, ฮ”) โІ (๐›พ, ฮ”)๐‘. By hypothesis, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›พ, ฮ”)๐‘ โˆˆ แฟ˜. But (๐›พ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›พ, ฮ”) = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›พ, ฮ”)๐‘. Thus, (๐›พ, ฮ”) โˆˆ แฟ˜ from Definition 1.17. (โ‡) Assume that (๐œ—, ฮ”) โІ (๐›ฟ, ฮ”) and (๐›ฟ, ๐›ฅ) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Then, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›ฟ, ฮ”) = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›ฟ, ฮ”)๐‘ is a ๐‘ ๐‘†ฦ„โˆ— โˆ’closed set and ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›ฟ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\ (๐›ฟ, ฮ”). By assumption, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›ฟ, ฮ”) โˆˆ แฟ˜. So, (๐œ—, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. Theorem 2.9: If (๐›พ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) and (๐›พ, ฮ”) โІ (๐›ฟ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)), then (๐›ฟ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. Proof. Let (๐›ฟ, ฮ”) โІ (๐œ‰, ฮ”) and (๐œ‰, ฮ”) is ๐‘ ๐‘†ฦ„โˆ— โˆ’open. Then, (๐›พ, ฮ”) โІ (๐œ‰, ฮ”). Since (๐›พ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed, then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐œ‰, ฮ”) โˆˆ แฟ˜. Now, (๐›ฟ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) implies that ๐‘๐‘™(๐›ฟ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)). Thus, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›ฟ, ฮ”))\(๐œ‰, ฮ”) โІ ๐‘๐‘™(๐›ฟ, ฮ”)\(๐œ‰, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\ (๐œ‰, ฮ”). So, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›ฟ, ฮ”))\(๐œ‰, ฮ”) โˆˆ แฟ˜ from Definition 1.17. Thus, (๐›ฟ, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed. The intersection of two ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed sets need not be a ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed as shown by the following example. Example 2.10: In Example 2.2, the soft sets (๐œ—, ฮ”), (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed. But (๐œ‰, ฮ”) = (๐œ—, ฮ”) โˆฉ (๐›ฟ, ฮ”) is not sSฦ„โˆ—แฟ˜ โˆ’closed, where (๐œ‰, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {ํœ€})}. Theorem 2.11: If (๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’closed and (๐›พ, ฮ”) is soft closed in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ). Then, (๐œ—, ฮ”) โˆฉ (๐›พ, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’closed. Proof. Let (๐œ—, ฮ”) โˆฉ (๐›พ, ฮ”) โІ (๐›ฟ, ฮ”) and (๐›ฟ, ๐›ฅ) is a sSฦ„โˆ— โˆ’open. Then (๐œ—, ฮ”) โІ (๐›ฟ, ฮ”) โˆช (๐›พ, ฮ”)๐‘. Since (๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’closed, so ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\((๐›ฟ, ฮ”) โˆช (๐›พ, ฮ”)๐‘) โˆˆ แฟ˜. Now, ๐‘๐‘™ (๐‘–๐‘›๐‘ก((๐œ—, ฮ”) โˆฉ (๐›พ, ฮ”))) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ ๐‘๐‘™(๐›พ, ฮ”) = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›พ, ฮ”) = [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›พ, ฮ”)]\(๐›พ, ฮ”)๐‘. Thus, ๐‘๐‘™ (๐‘–๐‘›๐‘ก((๐œ—, ฮ”) โˆฉ (๐›พ, ฮ”))) \ (๐›ฟ, ฮ”) โІ [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›พ, ฮ”)]\((๐›ฟ, ฮ”) โˆช (๐›พ, ฮ”)๐‘) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 289 https://internationalpubls.com โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\((๐›ฟ, ฮ”) โˆช (๐›พ, ฮ”)๐‘) โˆˆ แฟ˜ So, (๐œ—, ฮ”) โˆฉ (๐›พ, ฮ”) is sS ฦ„โˆ—แฟ˜ โˆ’closed. Theorem 2.12: Let (๐’ต, ๐”š, ๐›ฅ) is ๐’ฎTS and (๐›พ, ฮ”), (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed. Then (๐›พ, ฮ”) โˆช (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed. Proof. Let (๐›พ, ฮ”) and (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed. Suppose that (๐›พ, ฮ”) โˆช (๐›ฟ, ฮ”) โІ (๐œ—, ฮ”) and (๐œ—, ฮ”) is sSฦ„โˆ— โˆ’open. Then (๐›พ, ฮ”) โІ (๐œ—, ฮ”) and (๐›ฟ, ฮ”) โІ (๐œ—, ฮ”). Since (๐›พ, ฮ”) and (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed sets, then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐œ—, ฮ”) โˆˆ แฟ˜ and ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›ฟ, ฮ”))\(๐œ—, ฮ”) โˆˆ แฟ˜. Therefore, ๐‘๐‘™ (๐‘–๐‘›๐‘ก((๐›พ, ฮ”) โˆช (๐›ฟ, ฮ”))) \ (๐œ—, ฮ”) = [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(๐œ—, ฮ”)] โˆช [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›ฟ, ฮ”))\(๐œ—, ฮ”)] โˆˆ แฟ˜. Hence, we obtain that (๐›พ, ฮ”) โˆช (๐›ฟ, ฮ”) are sSฦ„โˆ—แฟ˜ โˆ’closed. Theorem 2.13: Let (๐’Ÿ, โ„ง, ๐›ฅ) be a soft subspace of a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ), and (โ„œ, ฮ”) is a soft subset of (๐’Ÿ, โ„ง, ๐›ฅ) and (๐›พ, ฮ”) โІ (โ„œ, ฮ”) and (๐›พ, ฮ”) is a sSฦ„โˆ—แฟ˜ โˆ’closed in (๐’ต, ๐”š, ๐›ฅ). Then, (๐›พ, ฮ”) is a sSฦ„โˆ—แฟ˜๐’Ÿ โˆ’closed in (๐’Ÿ, โ„ง, ๐›ฅ). Proof. Assume that (๐›พ, ฮ”) โІ (โ„’, ฮ”) โˆฉ (โ„œ, ฮ”) and (โ„’, ฮ”) โˆˆ ๐”š. Then (โ„’, ฮ”) โˆฉ (โ„œ, ฮ”) โˆˆ โ„ง and (๐›พ, ฮ”) โІ (โ„’, ฮ”). Since (๐›พ, ฮ”) is a sSฦ„โˆ—แฟ˜ โˆ’closed in (๐’ต, ๐”š, ๐›ฅ), then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\ (โ„’, ฮ”) โˆˆ แฟ˜. Now, [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) โˆฉ (โ„œ, ฮ”)] \ [(โ„’, ฮ”) โˆฉ (โ„œ, ฮ”)] = [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”))\(โ„’, ฮ”)] โˆฉ (โ„œ, ฮ”) โˆˆ แฟ˜๐’Ÿ Thus, (๐›พ, ฮ”) is a sSฦ„โˆ—แฟ˜๐’Ÿ โˆ’closed in (๐’Ÿ, โ„ง, ๐›ฅ). 3. Soft Strongly ฦ„โˆ— โˆ’open via soft ideal In this section, we define sSฦ„โˆ— โˆ’open set via soft ideal in ๐’ฎTSs. Definition 3.1: A soft set (๐›พ, ฮ”) in ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ), is called a soft stongly ฦ„โˆ—แฟ˜ โˆ’open set with respect to soft ideal แฟ˜ (sSฦ„โˆ—แฟ˜ โˆ’open) if and only if its relative complement (๐›พ, ฮ”)๐‘ is sSฦ„โˆ—แฟ˜ โˆ’closed in (๐’ต, ๐”š, ๐›ฅ). Example 3.2: In Example 2.2. the soft sets (๐›พ1, ฮ”)๐‘, (๐›พ2, ฮ”)๐‘ and (๐›พ3, ฮ”)๐‘ are sSฦ„โˆ—แฟ˜ โˆ’open where (๐›พ1, ฮ”)๐‘, (๐›พ2, ฮ”)๐‘ and (๐›พ3, ฮ”)๐‘ are given by (๐›พ1, ฮ”)๐‘ = {(โˆ‡1, ๐’ต), (โˆ‡2, โˆ…)}, (๐›พ1, ฮ”)๐‘ = {(โˆ‡1, โˆ…), (โˆ‡2, {๐œ‡})} and (๐›พ3, ฮ”)๐‘ = {(โˆ‡1, {ํœ€}), (โˆ‡2, {๐œ‡})}. Theorem 3.3: A soft set (๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) if and only if (๐›พ, ฮ”) \ (โ„’, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) for some (โ„’, ฮ”) โˆˆ แฟ˜, whenever (๐›พ, ฮ”) โІ (๐œ—, ฮ”) and (๐›พ, ฮ”) is soft closed in (๐’ต, ๐”š, ๐›ฅ). Proof. (โ‡’) Let (๐›พ, ฮ”) โІ (๐œ—, ฮ”) and (๐›พ, ฮ”) is soft closed. Then (๐œ—, ฮ”)๐‘ โІ (๐›พ, ฮ”)๐‘, (๐œ—, ฮ”)๐‘ is a sSฦ„โˆ—แฟ˜ โˆ’closed and (๐›พ, ฮ”)๐‘ โˆˆ ๐”š. By assumption, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) \ (๐›พ, ฮ”)๐‘ โˆˆ แฟ˜. Then ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) \ (๐›พ, ฮ”)๐‘ = (๐œ‚, ฮ”) for some (๐œ‚, ฮ”) โˆˆ แฟ˜. Thus, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) \ (๐›พ, ฮ”)๐‘ = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) โˆฉ (๐›พ, ฮ”) = (๐œ‚, ฮ”) โˆˆ แฟ˜. So, Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 290 https://internationalpubls.com E [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) โˆฉ (๐›พ, ฮ”)] โˆช (๐›พ, ฮ”)๐‘ = (๐œ‚, ฮ”) โˆช (๐›พ, ฮ”)๐‘. This implies that, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) โˆช (๐›พ, ฮ”)๐‘ = (โ„’, ฮ”) โˆช (๐›พ, ฮ”)๐‘. Hence, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) โІ (๐œ‚, ฮ”) โˆช (๐›พ, ฮ”)๐‘ for some (๐œ‚, ฮ”) โˆˆ แฟ˜. Furthermore, (๐œ‚, ฮ”) โˆช (๐›พ, ฮ”)๐‘ โІ [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘)]๐‘ = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)). Therefore, (๐›พ, ฮ”)\(๐œ‚, ฮ”) = (๐›พ, ฮ”) โˆฉ (๐œ‚, ฮ”)๐‘ โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)). (โ‡) Let (๐›พ, ฮ”)๐‘ โІ (๐›ฟ, ฮ”) such that (๐›ฟ, ฮ”) is sSฦ„โˆ— โˆ’open. Then, (๐›ฟ, ฮ”)๐‘ โІ (๐œ—, ฮ”). By assumption, (๐›ฟ, ฮ”)๐‘\(ฮ“, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) = [๐‘๐‘™(๐‘๐‘™(๐œ—, ฮ”)๐‘)]๐‘ for some (ฮ“, ฮ”) โˆˆ แฟ˜. Thus, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘) = ๐‘๐‘™(๐‘๐‘™(๐œ—, ฮ”)๐‘) โІ [(๐›ฟ, ฮ”)๐‘\(ฮ“, ฮ”)]๐‘ = (๐›ฟ, ฮ”) โˆช (ฮ“, ฮ”). So, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘)\(๐›ฟ, ฮ”) โІ [(๐›ฟ, ฮ”) โˆช (ฮ“, ฮ”)] โˆฉ (๐›ฟ, ฮ”)๐‘ = (ฮ“, ฮ”) โˆฉ (๐›ฟ, ฮ”)๐‘ โІ (ฮ“, ฮ”) โˆˆ แฟ˜ This shows that, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)๐‘)\(๐›ฟ, ฮ”) โˆˆ แฟ˜. Therefore, (๐œ—, ฮ”)๐‘is sSฦ„โˆ—แฟ˜ โˆ’closed and hence (๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open. Theorem 3.4: (1) Every open soft set is sSฦ„โˆ—แฟ˜ โˆ’open. (2) Every soft แฟ˜g โˆ’open set is sSฦ„โˆ—แฟ˜ โˆ’open. Proof. Immediate from Theorem 2.3. The converse of the above theorem is not true in general as shall show in the following examples. Example 3.5: In Example 2.2, the soft set (๐œ“, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open but not open soft set, where (๐œ“, ฮ”) = {(โˆ‡1, โˆ…), (โˆ‡2, {๐œ‡})}. Example 3.6: In Example 2.5, the soft set (๐œ‚, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open but not soft แฟ˜g โˆ’open, where (๐œ‚, ฮ”) = {(โˆ‡1, ๐’ต), (โˆ‡2, {ํœ€})}. The soft intersection (resp. union) of two sSฦ„โˆ—แฟ˜ โˆ’open sets need not be a sSฦ„โˆ—แฟ˜ โˆ’open as shown by the following example. Example 3.7: In Example 2.2, the soft sets (๐›พ1, ฮ”)๐‘, (๐›พ2, ฮ”)๐‘, (๐›พ3, ฮ”)๐‘ are sSฦ„โˆ—แฟ˜ โˆ’open. But (โ„’, ฮ”) = (๐›พ1, ฮ”)๐‘ โˆช (๐›พ2, ฮ”)๐‘ is not sSฦ„โˆ—แฟ˜ โˆ’open, where (โ„’, ฮ”) = {(โˆ‡1, ๐’ต), (โˆ‡2, {๐œ‡})}. Theorem 3.8: If (๐›พ, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) and ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐›พ, ฮ”)) โІ (๐›ฟ, ฮ”) โІ (๐›พ, ฮ”), then (๐›ฟ, ฮ”) is a sSฦ„โˆ—แฟ˜ โˆ’open. Proof. Let (๐œ‚, ฮ”) โІ (๐›ฟ, ฮ”) and (๐œ‚, ฮ”) is a sSฦ„โˆ—แฟ˜ โˆ’closed. Then, (๐œ‚, ฮ”) โІ (๐›พ, ฮ”). Since (๐›พ, ฮ”) is sS ฦ„โˆ—แฟ˜ โˆ’open, then (๐›ฟ, ฮ”)\๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ‚, ฮ”)) โІ (๐›พ, ฮ”)\๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ‚, ฮ”)) โˆˆ แฟ˜. It follows that, (๐›ฟ, ฮ”)\๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ‚, ฮ”)) โˆˆ แฟ˜. Thus, (๐›ฟ, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open. Theorem 3.9: A soft set (๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’closed in a ๐’ฎTS (๐’ต, ๐”š, ๐›ฅ) if and only if ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 291 https://internationalpubls.com Proof. (โ‡’) Let (๐›พ, ฮ”) โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) and (๐›พ, ฮ”) be a soft closed set. Then, (๐›พ, ฮ”) โˆˆ แฟ˜ from Theorem 2.9 so there exists (๐œŽ, ฮ”) โˆˆ แฟ˜ such that (๐›พ, ฮ”)\(๐œŽ, ฮ”) = โˆ…ฬƒ. Thus, that (๐›พ, ฮ”)\(๐œŽ, ฮ”) = โˆ…ฬƒ โІ ๐‘–๐‘›๐‘ก(๐‘๐‘™[๐‘๐‘™(๐œ—, ฮ”)\(๐œ—, ฮ”)]). Hence, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”) is a sSฦ„โˆ—แฟ˜ โˆ’open from Theorem 3.3. (โ‡) Let (๐œ—, ฮ”) โІ (๐›ฟ, ฮ”) such that (๐›ฟ, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’open. Then, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›ฟ, ฮ”)๐‘ โІ ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐œ—, ฮ”)๐‘ = ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”). By hypothesis, [๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›ฟ, ฮ”)๐‘]\ (๐œŽ, ฮ”) โІ ๐‘–๐‘›๐‘ก(๐‘๐‘™[๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐œ—, ฮ”)]) = โˆ…ฬƒ, for some (๐œŽ, ฮ”) โˆˆ แฟ˜ from Theorem 3.3. So, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”)) โˆฉ (๐›ฟ, ฮ”)๐‘ โІ (๐œŽ, ฮ”) โˆˆ แฟ˜. Thus, ๐‘๐‘™(๐‘–๐‘›๐‘ก(๐œ—, ฮ”))\(๐›ฟ, ฮ”) โˆˆ แฟ˜. So, (๐œ—, ฮ”) is a sS ฦ„โˆ—แฟ˜ โˆ’closed. 4. SS ฦ„โˆ— โˆ’continuous via soft ideal In this section, we introduce a sSฦ„โˆ— โˆ’continuous function with respect to a soft ideal in ๐’ฎTSs. Definition 4.1: Let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a soft mapping. If ๐›บโˆ’1((๐›ฟ, ฮ”)) is sSฦ„โˆ—แฟ˜ โˆ’open in (๐’ต, ๐”š, ๐›ฅ) for each soft open set (๐›ฟ, ฮ”) of (๐’Ÿ, โ„ง, ฮ˜), then ๐›บ is called soft strongly ฦ„โˆ—แฟ˜ โˆ’continuous function. Corollary 4.2: Let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a soft function. Then: 1- Every soft continuous function is sSฦ„โˆ—แฟ˜ โˆ’continuous functions. 2- Every soft แฟ˜g โˆ’continuous is sSฦ„โˆ—แฟ˜ โˆ’continuous function. Proof. Immediate from Theorem 3.4. The converse of the above theorem is not true in general as shall show in the following example. Example 4.3: Let ๐’ต = {ํœ€, ๐œ‡} and โˆ†= {โˆ‡1, โˆ‡2} . Let (๐›พ1, ฮ”), (๐›พ2, ฮ”) be two soft sets where (๐›พ1, ฮ”) = {(โˆ‡1, {ํœ€})}, (๐›พ2, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, {๐œ‡})}. ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ1, ฮ”), (๐›พ2, ฮ”)} is the soft topology over ๐’ต. Let แฟ˜ = {โˆ…ฬƒ} be a soft ideal on ๐’ต. Let ๐’Ÿ = {๐œŽ, ๐œŒ} and ฮ˜ = {ฯฑ1, ๐œš2}, โ„ง = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›ฟ, ฮ˜)} is soft topology on ๐’Ÿ. Where (๐›ฟ, ฮ˜) = {(ฯฑ1, {๐œŽ}), (ฯฑ2, {๐œŽ})}. Then let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a soft function and ๐‘ข: ๐’ต โ†’ ๐’Ÿ and ๐‘: โˆ†โ†’ ฮ˜ denoted by ๐‘ข(ํœ€) = ๐œŽ, ๐‘ข(๐œ‡) = ๐œŒ, ๐‘(โˆ‡1) = ฯฑ1, ๐‘(โˆ‡2) = ฯฑ2. Let take (๐œ—, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, {ํœ€})}. Then ๐›บ is sSฦ„โˆ—แฟ˜ โˆ’continuous but not soft continuous. Since If ๐›บโˆ’1((๐›ฟ, ฮ˜)) = (๐œ—, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’open set but not soft open set. Example 4.4: Let ๐’ต = {ํœ€, ๐œ‡, ๐œ”} and โˆ†= {โˆ‡1, โˆ‡2} . Let (๐›พ1, ฮ”), (๐›พ2, ฮ”) and (๐›พ3, ฮ”) be soft sets where: (๐›พ1, ฮ”) = {(โˆ‡1, {ํœ€}, (โˆ‡2, {ํœ€}))}, (๐›พ2, ฮ”) = {(โˆ‡1, {๐œ‡}), (โˆ‡2, โˆ…)} and Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 292 https://internationalpubls.com (๐›พ3, ฮ”) = {(โˆ‡1, {ํœ€, ๐œ”}), (โˆ‡2, {ํœ€})} and ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ1, ฮ”), (๐›พ2, ฮ”), (๐›พ3, ฮ”)} is the soft topology over ๐’ต. Let แฟ˜ = {โˆ…ฬƒ} be a soft ideal on ๐’ต. Let ๐’Ÿ = {๐œŽ, ๐œŒ, ๐œ‹} and ฮ˜ = {ฯฑ1, ๐œš2}, โ„ง = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›ฟ, ฮ˜)} is soft topology on ๐’Ÿ. Where (๐›ฟ, ฮ˜) = {(ฯฑ1, {๐œŽ}), (ฯฑ1, โˆ…)}. Then let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a soft function and ๐‘ข: ๐’ต โ†’ ๐’Ÿ and ๐‘: โˆ†โ†’ ฮ˜ denoted by ๐‘ข(ํœ€) = ๐œŽ, ๐‘ข(๐œ‡) = ๐œŒ, ๐‘ข(๐œ”) = ๐œ‹, ๐‘(โˆ‡1) = ฯฑ1, ๐‘(โˆ‡2) = ฯฑ2. Let take (๐œ—, ฮ”) = {(โˆ‡1, {ํœ€}), (โˆ‡2, โˆ…)}. Then ฮฉ is sSฦ„โˆ—แฟ˜ โˆ’continuous but not soft แฟ˜g โˆ’continuous. Since If ๐›บโˆ’1((๐›ฟ, ฮ˜)) = (๐œ—, ฮ”) is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’closed set but not soft แฟ˜g โˆ’closed set. Definition 4.5: Let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a soft mapping. If ๐›บโˆ’1((๐›ฟ, ฮ”)) is sSฦ„โˆ—แฟ˜ โˆ’closed in (๐’ต, ๐”š, ๐›ฅ) for each sSฦ„โˆ— โˆ’closed set (๐›ฟ, ฮ”) of (๐’Ÿ, โ„ง, ฮ˜), then ๐›บ is said to be soft strongly ฦ„โˆ—แฟ˜ โˆ’irresolute function. Theorem 4.6: A map ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) is sSฦ„โˆ— โˆ’ ๐‘–๐‘Ÿ๐‘Ÿ๐‘’๐‘ ๐‘œ๐‘™๐‘ข๐‘ก๐‘’ if and only if the inverse image of every soft strongly ฦ„โˆ—แฟ˜ โˆ’ ๐‘œ๐‘๐‘’๐‘› set in ๐’Ÿ is soft strongly ฦ„โˆ— โˆ’ ๐‘œ๐‘๐‘’๐‘› in ๐’ต. Proof. Clearly. Theorem 4.8: Every sSฦ„โˆ—แฟ˜ โˆ’irresolute mapping is sSฦ„โˆ—แฟ˜ โˆ’continuous functions. Proof. Let ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) be a sSฦ„โˆ—แฟ˜ โˆ’irresolute mapping. Let (๐›ฟ, ฮ”) be a soft closed set in ๐’Ÿ. Then (๐›ฟ, ฮ”) is sSฦ„โˆ—แฟ˜ โˆ’closed set in ๐’Ÿ. Since ๐›บ is sSฦ„โˆ—แฟ˜ โˆ’irresolute mapping, ๐›บโˆ’1((๐›ฟ, ฮ”)) is sSฦ„โˆ—แฟ˜ โˆ’closed set in ๐’ต. Hence, ๐›บ is sSฦ„โˆ—แฟ˜ โˆ’ccontinuous function. Definition 4.9: A soft mapping ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) is said to be soft strongly ฦ„โˆ—แฟ˜ โˆ’open (soft strongly ฦ„โˆ—แฟ˜ โˆ’closed ) map if the image of every soft ๐‘œ๐‘๐‘’๐‘› (soft ๐‘๐‘™๐‘œ๐‘ ๐‘’๐‘‘) set in ๐’ต is sSฦ„โˆ—แฟ˜ โˆ’open (sSฦ„โˆ—แฟ˜ โˆ’closed) set in ๐’Ÿ. Remark 4.10: (1) Every soft open map is sSฦ„โˆ—แฟ˜ โˆ’open. (2) Every sSฦ„โˆ—แฟ˜ โˆ’open map is sSฦ„โˆ— โˆ’open. In the following examples as observed the converses are not true. Example 4.11: Let ๐’ต = {ํœ€, ๐œ‡} and โˆ†= {โˆ‡1, โˆ‡2} . ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ, ฮ”)} is the soft topology over ๐’ต where (๐›พ, ฮ”) = {(โˆ‡1, {ํœ€})}. Let ๐ฝ = {โˆ…ฬƒ} be a soft ideal on ๐’ต. Also, let ๐’Ÿ = {๐œŽ, ๐œŒ} and ฮ˜ = {ฯฑ1, ๐œš2}, โ„ง = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›ฟ1, ฮ˜), (๐›ฟ2, ฮ˜)} is soft topology on ๐’Ÿ. Where (๐›ฟ1, ฮ˜) = {(ฯฑ1, {๐œŽ}), (ฯฑ2, {๐œŒ})} and (๐›ฟ2, ฮ˜) = {(ฯฑ1, {๐œŒ}), (ฯฑ2, {๐œŽ})}. Then the soft function ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) where ๐‘ข: ๐’ต โ†’ ๐’Ÿ and ๐‘: โˆ†โ†’ ฮ˜ denoted by ๐‘ข(ํœ€) = ๐œŽ, ๐‘ข(๐œ‡) = ๐œŒ, ๐‘ข(๐œ”) = ๐œ‹, ๐‘(โˆ‡1) = ฯฑ1, ๐‘(โˆ‡2) = ฯฑ2 is sSฦ„โˆ—แฟ˜ โˆ’open but not soft open. Since for each soft open (๐›พ, ฮ”) in ๐’ต, ๐›บ((๐›พ, ฮ”)) = (๐œ—, ฮ˜) = {(ฯฑ1, {๐œŽ})} is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’open set but not soft open set. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 31 No. 2 (2024) 293 https://internationalpubls.com Example 4.12: Let ๐’ต = {ํœ€, ๐œ‡} and โˆ†= {โˆ‡1, โˆ‡2} . ๐”š = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›พ, ฮ”)} is the soft topology over ๐’ต where (๐›พ, ฮ”) = {(โˆ‡1, ๐’ต), (โˆ‡1, {ํœ€})}. Also, let ๐’Ÿ = {๐œŽ, ๐œŒ} and ฮ˜ = {ฯฑ1, ๐œš2}, โ„ง = {๏ฟฝฬƒ๏ฟฝ, โˆ…ฬƒ, (๐›ฟ1, ฮ˜), (๐›ฟ2, ฮ˜)} is soft topology on ๐’Ÿ, where (๐›ฟ1, ฮ˜) = {(ฯฑ1, {๐œŽ})} and (๐›ฟ2, ฮ˜) = {(ฯฑ1, {๐œŽ}), (ฯฑ2, {๐œŒ})}. Let ๐ฝ = ๐‘ƒ(๐’Ÿ) be a soft ideal on ๐’Ÿ. Then the soft function ๐›บ: (๐’ต, ๐”š, ๐›ฅ) โ†’ (๐’Ÿ, โ„ง, ฮ˜) where ๐‘ข: ๐’ต โ†’ ๐’Ÿ and ๐‘: โˆ†โ†’ ฮ˜ denoted by ๐‘ข(ํœ€) = ๐œŽ, ๐‘ข(๐œ‡) = ๐œŒ, ๐‘ข(๐œ”) = ๐œ‹, ๐‘(โˆ‡1) = ฯฑ1, ๐‘(โˆ‡2) = ฯฑ2 is sSฦ„โˆ—แฟ˜ โˆ’open but not sSฦ„โˆ— โˆ’open. Since for each soft open (๐›พ, ฮ”) in ๐’ต, ๐›บ((๐›พ, ฮ”)) = (๐œ—, ฮ˜) = {(ฯฑ1, ๐’Ÿ), (ฯฑ1, {๐œŽ})} is ๐‘ ๐‘†ฦ„โˆ—แฟ˜ โˆ’open set but not ๐‘ ๐‘†ฦ„โˆ— โˆ’open set. 5. Conclusions In this work, we study the sSฦ„โˆ—แฟ˜ โˆ’closed sets and sSฦ„โˆ—แฟ˜ โˆ’open sets and some of their properties and investigated. Also, we define the sSฦ„โˆ—แฟ˜ โˆ’continuous and sSฦ„โˆ—แฟ˜ โˆ’irresolute. In future, more general types of sSฦ„โˆ—แฟ˜ โˆ’closed sets may be defined and using of them characterizations related with soft separation axioms and soft continuity may be studied. References [1] D. Molodtsov, "Soft set theory-first results," Computers and Mathematics with Applications, vol. 37, no. 4-5, pp. 19-31, 1999. [2] I. 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