The Free On-line Dictionary of Computing (30 December 2018):

neutrosophic set

    A generalisation of the intuitionistic set,
   classical set, fuzzy set, paraconsistent set, dialetheist
   set, paradoxist set, tautological set based on
   Neutrosophy.  An element x(T, I, F) belongs to the set in
   the following way: it is t true in the set, i indeterminate in
   the set, and f false, where t, i, and f are real numbers taken
   from the sets T, I, and F with no restriction on T, I, F, nor
   on their sum n=t+i+f.

   The neutrosophic set generalises:

   - the intuitionistic set, which supports incomplete set
   theories (for 0fuzzy set (for n=100 and i=0, and 0<=t,i,f<=100);

   - the classical set (for n=100 and i=0, with t,f either 0 or
   100);

   - the paraconsistent set (for n>100 and i=0, with both
   t,f<100);

   - the dialetheist set, which says that the intersection of
   some disjoint sets is not empty (for t=f=100 and i=0; some
   paradoxist sets can be denoted this way).

   (http://gallup.unm.edu/~smarandache/NeutSet.txt).

   ["Neutrosophy / Neutrosophic Probability, Set, and Logic",
   Florentin Smarandache, American Research Press, 1998].

   (1999-12-14)