In this paper, we present the lattice structures of neutrosophic theories. We prove that Zhang-Zhang’s YinYang bipolar fuzzy set is a subclass of the Single-Valued bipolar neutrosophic set. Then we show that the pair structure is a particular case of refined neutrosophy, and the number of types of neutralities (sub-indeterminacies) may be any finite or infinite number.

In this paper, we present the lattice structures of neutrosophic theories. We prove that Zhang-Zhang’s YinYang bipolar fuzzy set is a subclass of the Single-Valued bipolar neutrosophic set. Then we show that the pair structure is a particular case of refined neutrosophy, and the number of types of neutralities (sub-indeterminacies) may be any finite or infinite number.

This ninth volume of Collected Papers includes 87 papers comprising 982 pages on Neutrosophic Theory and its applications in Algebra, written between 2014-2022 by the author alone or in collaboration with the following 81 co-authors (alphabetically ordered) from 19 countries: E.O. Adeleke, A.A.A. Agboola, Ahmed B. Al-Nafee, Ahmed Mostafa Khalil, Akbar Rezaei, S.A. Akinleye, Ali Hassan, Mumtaz Ali, Rajab Ali Borzooei , Assia Bakali, Cenap Özel, Victor Christianto, Chunxin Bo, Rakhal Das, Bijan Davvaz, R. Dhavaseelan, B. Elavarasan, Fahad Alsharari, T. Gharibah, Hina Gulzar, Hashem Bordbar, Le Hoang Son, Emmanuel Ilojide, Tèmítópé Gbóláhàn Jaíyéolá, M. Karthika, Ilanthenral Kandasamy, W.B. Vasantha Kandasamy, Huma Khan, Madad Khan, Mohsin Khan, Hee Sik Kim, Seon Jeong Kim, Valeri Kromov, R. M. Latif, Madeleine Al-Tahan, Mehmat Ali Ozturk, Minghao Hu, S. Mirvakili, Mohammad Abobala, Mohammad Hamidi, Mohammed Abdel-Sattar, Mohammed A. Al Shumrani, Mohamed Talea, Muhammad Akram, Muhammad Aslam, Muhammad Aslam Malik, Muhammad Gulistan, Muhammad Shabir, G. Muhiuddin, Memudu Olaposi Olatinwo, Osman Anis, Choonkil Park, M. Parimala, Ping Li, K. Porselvi, D. Preethi, S. Rajareega, N. Rajesh, Udhayakumar Ramalingam, Riad K. Al-Hamido, Yaser Saber, Arsham Borumand Saeid, Saeid Jafari, Said Broumi, A.A. Salama, Ganeshsree Selvachandran, Songtao Shao, Seok-Zun Song, Tahsin Oner, M. Mohseni Takallo, Binod Chandra Tripathy, Tugce Katican, J. Vimala, Xiaohong Zhang, Xiaoyan Mao, Xiaoying Wu, Xingliang Liang, Xin Zhou, Yingcang Ma, Young Bae Jun, Juanjuan Zhang.

In this book, we approach different topics related to neutrosophics, such as: Neutrosophic Set, Intuitionistic Fuzzy Set, Inconsistent Intuitionistic Fuzzy Set, Picture Fuzzy Set, Ternary Fuzzy Set, Pythagorean Fuzzy Set, Atanassov’s Intuitionistic Fuzzy Set of second type, Spherical Fuzzy Set, n-HyperSpherical Neutrosophic Set, q-Rung Orthopair Fuzzy Set, truth-membership, indeterminacy-membership, falsehood-nonmembership, Regret Theory, Grey System Theory, Three-Ways Decision, n-Ways Decision, Neutrosophy, Neutrosophication, Neutrosophic Probability, Refined Neutrosophy, Refined Neutrosophication, Nonstandard Analysis; Extended Nonstandard Analysis; Open and Closed Monads to the Left/Right; Pierced and Unpierced Binads; and so on.

Neutrosophy as science has inclusive attributes that make possible to extract the contributions of neutral values in the analysis of data sets; it builds a unified field of logic for transdisciplinary studies that transcend the boundaries between natural and social sciences. Neutral philosophy seeks to solve the problems of indeterminacy that appear universally, to reform the current natural or social sciences, with an open methodology to promote innovation. The research products related in this special issue start from the premise that the difficulty is not the complexity of the social environment, but the instrumental obsolescence to observe, interpret and manage that complexity, there are bold approaches and proposals for valid solutions that come to enrich the universe of resolution through the use of neutral methods. In the last year, the use of tools related to neutrosophy and its application to the social sciences, modeling of social phenomena based on simulation agents, problems associated with health, psychology, education, environmental management and sustainability solutions and legal sciences has increased in the events organized by the Asociacion Latinoamericana de Ciencias Neutrosoficas (ALCN in Spanish). The methods of higher incidence are cognitive maps, neutral Iadovs, neutral Delphi, analytical hierarchy process methods, neutral statistics, neutral personality models, among the most significant. In this special issue, there is a predominance of research from Ecuadorian universities, demonstrating how neutrosophy and its methods are consolidated as instruments of analysis, inference and research validation.

Contributors to current issue (listed in papers’ order): Noel Batista Hernández; C.V. Valenzuela Chicaiza; O.G. Arciniegas Paspuel; P.Y. Carrera Cuesta; D.R. Álvarez Hernández, C.E. Pozo Hernández; E.T. Mejía Álvarez; E.T. Villa Shagnay; S. Guerrón Enríquez; M.A. Tello Cadena; E.M. Pinos Medina; M. Jaramillo Burgos; F. Jara Vaca; R. Aguilar Berrezueta; E.M. Sandoval; B. Villalta Jadán; D. Palma Rivera; L.E. Valencia Cruzaty; M. Reyes Tomalá; C.M. Castillo Gallo, M.R. Velázquez; M.R. Mena Peralta; L. Ricardo Domínguez; D. Andrade Santamaría; X.Cangas Oña; M. Jaramillo Burgos; G.A. Calderón Vallejo; M. Orellana Cepeda; M.F. Galarza Villalba; M.S. Serrano Viteri; I. Ramos Castro; F. Vera Díaz; N.P. Lastra Calderón; D.L. Villarruel Delgado; D. Sandoval Malquín; E. Araujo Guerrón; A.R. Pupo Kairuz; D.V. Ponce Ruiz; F. Viteri Pita; F.S. Bustillo Mena; M.E. Narváez Jaramillo; M.A. Guerrero Ayala; D.A. Flores Jurado; O.M. Alonzo Pico; A.I. Utrera Velázquez; D.A. García Coello; E. Real Garlobo; C. Escobar Vinueza; R.C. Hernández Infante; M.E. Infante Miranda; F.R. Rivadeneira Enríquez; C.J. Galeano Páez; R.M. Montalvo Pantoja; K.A. Narváez Ortiz; S. Guaytarilla Salas; A.D. Rodríguez Lara; C.P. Rendón Tello; J. Almeida Blacio; R. Hurtado Guevara; L.G. Guallpa Zatán; H.J. Paillacho Chicaiza; J. Yaguar Mariño; M. Aguilar Carrión; D.A. Viteri Intriago; L. Álvarez Gómez; D. Ponce Ruiz; L.H. Carrión Hurtado; W.R. Salas Espín; M. Benalcázar Paladines; L. Moreira Rosales; L.K. Baque Villanueva; M.A. Mendoza; R. Salcedo; A.M. Izquierdo Morán; M.A. Checa Cabrera; B.J. Ipiales Chasiguano; A.L. Sandoval Pillajo; R. Díaz Vázquez; N.P. Becerra Arévalo; M.F. Calles Carrasco; John Luis Toasa Espinoza; M. Velasteguí Córdova; V.M. Parrales Carvajal; M.T. Macías Valverde; R. Aguas Pután; N. García Arias; N. Quevedo Arnaiz; S. Gavilánez Villamarín; M. Cleonares Borbor; M.F. Galarza Villalba; R. Aguas Pután; J. Mora Romero; J.E. Espìn Oviedo; L.J. Molina Chalacán; L.O. Albarracín Zambrano; E.J. Jalón Arias; A. Zúñiga Paredes; F. Smarandache; J. Estupiñán Ricardo; E. González Caballero; M.Y. Leyva Vázquez.

In this ninth book of scilogs collected from my nest of ideas, one may find new and old questions and solutions, – in email messages to research colleagues, or replies, and personal notes, some handwritten on the planes to, and from international conferences, about topics on Neutrosophy and its applications, such as: Neutrosophic Bipolar Set, Linguistic Neutrosophic Set, Neutrosophic Resonance Frequency, n-ary HyperAlgebra, n-ary NeutroHyperAlgebra, n-ary AntiHyperAlgebra, Plithogenic Crisp Graph, Plithogenic Fuzzy Graph, Plithogenic Intuitionistic Fuzzy Graph, Plithogenic Neutrosophic Graph, Plithogenic Real Number Graph, Plithogenic Complex Number Graph, Plithogenic Neutrosophic Number Graph, and many more. Exchanging ideas with: Tareq Al-Shami, Riad Khidr Al-hamido, Mohammad Akram, B. De Baets, Robert Neil Boyd, Said Broumi, Terman Frometa-Castillo, Yilmaz Ceven, D. Dubois, Harish Garg, L. Godo, Erik Gonzalez, Yanhui Guo, Mohammad Hamidi, E. Hüllermeier, W. B. Vasantha Kandasamy, Mary Jansi, Nivetha Martin, Mani Parimala, Akbar Rezaei, Bouzina Salah, Christy Vincent, Jun Ye.