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P y
μ P (
) μ P (
)
μ P is an
[
,
]−
verifies: x
x
y
, and hence
0
1
degree for P in
[
,
]
[
,
]
that are around five.
Obviously, this degree does not perfectly reflect the primary use of P .
0
10
, that originates a fuzzy set P
of the numbers in
0
10
Example 1.1.8 Consider P
=
big in X
=[
0
,
10
]
. Let us show several possible
degrees for it, after agreeing that ' x
P y if and only if x
y , in the linear order of
[
0
,
10
]
'.
A
[
0
,
1
]
-degree
μ P is any function X
=[
0
,
10
]ₒ[
0
,
1
]
, such that
If x
y
,
then
μ P (
x
) μ P (
y
),
that is, any non-decreasing function (of which there are many). We can also agree
that
μ P (
0
) =
0, and
μ P (
10
) =
1. With this, it is clear that all degrees for big will
show some family resemblance .
Once fixed
(
L
, ) = ( [
0
,
1
] , )
, and
P
=
, the different uses of big only
depend on which function
μ P is chosen to reflect the meaning of the predicate in
[
0
,
10
]
. Of course, it is
P = μ P if and only if function
μ P is strictly non-decreasing,
x 2
as it is the case either with
μ P (
x
) =
x
/
10, or with
μ P (
x
) =
/
100. Provided
μ P
is not strictly non-decreasing as, for example, with
P 4 (strictly), but
μ P (
) = μ P (
) =
.
μ P does not perfectly reflect the
since 6
6
4
0
5,
primary use of big in
[
0
,
10
]
. In the same way, the crisp degree
1
,
if
x
>
8
μ P (
x
) =
0
,
otherwise
,
does not perfectly reflect the primary use of big when translated into 'after eight'.
Another possible model for
μ P is
0
,
if
x
∈[
0
,
2
]
x
2
μ P (
x
) =
,
if
x
∈[
2
,
8
]
6
1
if
x
∈[
8
,
10
] ,
with graphic.
 
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