In this article, we will look at the definition of rough neutrosophic set in semigroups and investigate their properties. We also introduce the concept of rough Neutrosophic (right,left,two-sided,bi-) ideals in a semigroup and study some properties of the ideals of semigroup.

The topics discussed in this book are Int-soft semigroup, Int-soft left (right) ideal, Int-soft (generalized) bi-ideal, Int-soft quasi-ideal, Int-soft interior ideal, Int-soft left (right) duo semigroup, starshaped (∈, ∈∨ qk)-fuzzy set, quasi-starshaped (∈, ∈∨ qk)-fuzzy set, semidetached mapping, semidetached semigroup, (∈, ∈ ∨qk)-fuzzy subsemi-group, (qk, ∈ ∨qk)-fuzzy subsemigroup, (∈, ∈ ∨ qk)-fuzzy subsemigroup, (qk, ∈ ∨ qk)-fuzzy subsemigroup, (∈ ∨ qk, ∈ ∨ qk)-fuzzy subsemigroup, (∈, ∈∨ qkδ)-fuzzy subsemigroup, ∈∨ qkδ -level subsemigroup/bi-ideal, (∈, ∈∨ qkδ )-fuzzy (generalized) bi-ideal, δ-lower (δ-upper) approximation of fuzzy set, δ-lower (δ-upper) rough fuzzy subsemigroup, δ-rough fuzzy subsemigroup, Neutrosophic N -structure, neutrosophic N -subsemigroup, ε-neutrosophic N -subsemigroup, and neutrosophic N -product.

Neutrosophy (1995) is a new branch of philosophy that studies triads of the form (, , ), where is an entity (i.e., element, concept, idea, theory, logical proposition, etc.), is the opposite of , while is the neutral (or indeterminate) between them, i.e., neither nor . Based on neutrosophy, the neutrosophic triplets were founded; they have a similar form: (x, neut(x), anti(x), that satisfy some axioms, for each element x in a given set. This book contains the successful invited submissions to a special issue of Symmetry, reporting on state-of-the-art and recent advancements of neutrosophic triplets, neutrosophic duplets, neutrosophic multisets, and their algebraic structures—that have been defined recently in 2016, but have gained interest from world researchers, and several papers have been published in first rank international journals.

Neutrosophy (1995) is a new branch of philosophy that studies triads of the form (, , ), where is an entity {i.e. element, concept, idea, theory, logical proposition, etc.}, is the opposite of , while is the neutral (or indeterminate) between them, i.e., neither nor . Based on neutrosophy, the neutrosophic triplets were founded, which have a similar form (x, neut(x), anti(x)), that satisfy several axioms, for each element x in a given set. This collective book presents original research papers by many neutrosophic researchers from around the world, that report on the state-of-the-art and recent advancements of neutrosophic triplets, neutrosophic duplets, neutrosophic multisets and their algebraic structures – that have been defined recently in 2016 but have gained interest from world researchers. Connections between classical algebraic structures and neutrosophic triplet / duplet / multiset structures are also studied. And numerous neutrosophic applications in various fields, such as: multi-criteria decision making, image segmentation, medical diagnosis, fault diagnosis, clustering data, neutrosophic probability, human resource management, strategic planning, forecasting model, multi-granulation, supplier selection problems, typhoon disaster evaluation, skin lesson detection, mining algorithm for big data analysis, etc.

Smarandache algebraic structures that inter-relates two distinct algebraic structures and analyzes them relatively can be considered a paradigm shift in the study of algebraic structures. For instance, the algebraic structure Smarandache semigroup simultaneously involves both group and semigroup.Recently, Neutrosophic Algebraic Structures were introduced. This book ventures to define Smarandache Neutrosophic Algebraic Structures.Here, Smarandache neutrosophic structures of groups, semigroups, loops and groupoids and their N-ary structures are introduced and analyzed. There is a lot of scope for interested researchers to develop these concepts.

In this book authors build algebraic structures on fuzzy unit semi-open square UF = {(a,b), with a, b in [0, 1)} and on neutrosophic unit semi-open square UN = {a+bI, with a, b in [0, 1)}. As distributive laws are not true, we are not in a position to develop several properties of rings, semirigs and linear algebras. Seven open conjectures are proposed.

This book consists of seven chapters. In chapter one we introduced neutrosophic ideals (bi, quasi, interior, (m,n) ideals) and discussed the properties of these ideals. Moreover, we characterized regular and intra-regular AG-groupoids using these ideals. In chapter two we introduced neutrosophic minimal ideals in AG-groupoids and discussed several properties. In chapter three, we introduced different neutrosophic regularities of AG-groupoids. Further we discussed several condition where these classes are equivalent. In chapter four, we introduced neutrosophic M-systems and neutrosophic p-systems in non-associative algebraic structure and discussed their relations with neutrosophic ideals. In chapter five, we introduced neutrosophic strongly regular AG-groupoids and characterized this structure using neutrosophic ideals. In chapter six, we introduced the concept of neutrosophic ideal, neutrosophic prime ideal, neutrosophic bi-ideal and neutrosophic quasi ideal of a neutrosophic semigroup. With counter example we have shown that the union and product of two neutrosophic quasi-ideals of a neutrosophic semigroup need not be a neutrosophic quasi-ideal of neutrosophic semigroup. We have also shown that every neutrosophic bi-ideal of a neutrosophic semigroup need not be a neutrosophic quasi-ideal of a neutrosophic semigroup. We have also characterized the regularity and intra-regularity of a neutrosophic semigroup. In chapter seven, we introduced neutrosophic left almost rings and discussed several properties using their neutrosophic ideals. Keywords: neutrosophic set, algebraic structure, neutrosophic ideal, AG-groupoids, neutrosophic minimal ideals, neutrosophic regularities, neutrosophic M-systems, neutrosophic p-systems, neutrosophic strongly regular AG-groupoids neutrosophic prime ideal, neutrosophic bi-ideal, neutrosophic quasi ideal, neutrosophic semigroup, neutrosophic left almost rings