Three Decades of Neutrosophic and Plithogenic Theories with their Applications (1995 - 2024)

Abstract

Zadeh introduced the degree of membership/truth (T) in 1965 and defined the fuzzy set.
Atanassov introduced the degree of nonmembership/falsehood (F) in 1986 and defined the intuitionistic fuzzy set.
Smarandache introduced the degree of indeterminacy/neutrality (I) as independent component in 1995 (published in 1998) and he defined the neutrosophic set on three components:
(T, I, F) = (Truth, Indeterminacy, Falsehood), where in general T, I, F are subsets of the interval [0, 1]; in particular T, I, F may be intervals, hesitant sets, single-values, etc.;
Indeterminacy (or Neutrality), as independent component from the truth and from the falsehood, is the main distinction between Neutrosophic Theories and other classical and fuzzy theory or fuzzy extension theories: 

https://fs.unm.edu/Indeterminacy.pdf
See F. Smarandache, Neutrosophy / Neutrosophic probability, set, and logic", Proquest, Michigan, USA, 1998.

https://arxiv.org/ftp/math/papers/0101/0101228.pdf
https://fs.unm.edu/eBook-Neutrosophics6.pdf;
reviewed in Zentralblatt für Mathematik (Berlin, Germany): 

https://zbmath.org/?q=an:01273000
And cited by Denis Howe in The Free Online Dictionary of Computing, England, 1999.
Neutrosophic Set and Logic are generalizations of classical, fuzzy, and intuitionist fuzzy set and logic:
https://arxiv.org/ftp/math/papers/0404/0404520.pdf
https://arxiv.org/ftp/math/papers/0303/0303009.pdf