The Neutrosophic Multisets and the Neutrosophic
Multiset Algebraic Structures were introduced
by Florentin Smarandache [2, 3, 4] in 2016.
Let
be
a universe of discourse, and
.
A Neutrosophic Multiset is a neutrosophic set where one or
more elements are repeated
with the same neutrosophic components, or with different
neutrosophic components.
2. Examples

is a neutrosophic set (not a
neutrosophic multiset).
But

is a neutrosophic multiset, since
the element a is repeated; we say that the element a has
neutrosophic multiplicity 2 with the same neutrosophic components.
While

is also a neutrosophic multiset,
since the element a is repeated (it has neutrosophic
multiplicity 3),
but with different neutrosophic components, since, for example, during
the time,
the neutrosophic membership of an element may change.
If the element is repeated times keeping the same
neutrosophic components
,
we say that a has multiplicity .
But if there is some change in the neutrosophic components
of a, we say that a has the
neutrosophic multiplicity .
Therefore, we define in general the Neutrosophic
Multiplicity Function:

where
,
and for any
one
has

which means that a is
repeated
times
with the neutrosophic components
;
a is repeated
times
with the neutrosophic components
,
..., a is repeated
times
with the neutrosophic components
,
..., and so on.
Of course, all
,
and
,
for
,
with
.
Also, all neutrosophic components are with respect to the
set . Then, a neutrosophic
multiset
A can be written as:

or
.
3. Examples of operations with neutrosophic multisets.
Let's have:



Then:
1.3.1. Intersection of Neutrosophic Multisets.

1.3.2. Union of Neutrosophic Multisets.

1.3.3. Inclusion of Neutrosophic Multisets.
,
but

4. Cardinality of Neutrosophic Multisets.
,
and
3,
where
means
cardinal.
5. Cartesian Product of Neutrosophic Multisets.

6. Difference of Neutrosophic Multisets.



7. Sum of Neutrosophic Multisets.


Let's compute the neutrosophic multiplicity function, with
respect to several of the
previous neutrosophic multisets.







.
References
[1] Eric W. Weisstein, Multiset, MathWorld,
CRC Encyclopedia of Mathematics,
Boca Raton, FL, USA.
[2] F. Smarandache,
Neutrosophic Theory and Applications,
Le Quy
Don Technical University,
Faculty of Information technology,
Hanoi, Vietnam, 17th May 2016.
[3]
F. Smarandache, Neutrosphic Multiset
Applied in Physical Processes,
Actualization of the Internet of Things, a FIAP
Industrial Physics Conference,
Monterey, California, Jan. 2017.
[4] F. Smarandache,
Neutrosophic Perspectives: Triplets, Duplets, Multisets,
Hybrid Operators, Modal Logic, Hedge Algebras. And Applications. Pons
Editions, Bruxelles, 323 p., 2017;
CHAPTER X: 115-123
Neutrosophic Multiset: 115-119
Neutrosophic Multiset Applied in Physical Processes:
120-121
Neutrosophic Complex Multiset: 122-123.