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Interaction in Choquet inegral model

This paper studies the notion of interaction between criteria in a Choquet integral model.

This paper studies the notion of interaction between criteria in a Choquet integral model.

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[ ∑

=

=

K⊆N\A

[

µ(N) +

[ ∑

a∑

p=0,

p even

a∑

a∑

p=2,

p even

L⊆A,

l=a−p

L⊆A,

l=a−p

K⊆N\A p=0, L⊆A,

p even l=a−p−1

[ ∑

≥ µ(N) −

K⊆N\A

]

µ(K ∪ L)

[ ∑

µ((N \ A) ∪ L) +

]

µ(K ∪ L)

a∑

p=0,

p even

L⊆A,

l=a−p−1

K⊆N\A

]

µ(K ∪ L)

Therefore, (n − a + 1)!k! × I µ A ≥ µ(N) − [

[ ∑

We still have to prove that µ(N) −

a∑

p=0,

p even

KN\A

K⊆N\A

L⊆A,

l=a−p−1

a∑

p=0,

p even

K⊆N\A

a∑

p=0,

p even

L⊆A,

l=a−p

a∑

p=0,

p even

L⊆A,

l=a−p−1

]

µ(K ∪ L)

]

µ(K ∪ L) -

L⊆A,

l=a−p−1

]

µ(K ∪ L) .

]

µ(K ∪ L) > 0.

Let K ⊆ N \ A, p ∈ {0, . . . , a} even number and L ⊆ A with l = a − p − 1. We have

L A, therefore K ∪ L N, then by hypothesis not(a K∪L T C I∪M a N ). Thus a N ∈ B m

and there exists l K∪L ∈ {0, 1, . . . , m − 1} such that a K∪L ∈ B lK∪L .

Then µ(K ∪ L) = 1 α (2n)l K∪L

or µ(K ∪ L) = 0, so in both cases we have µ(K ∪ L) ≤

1

α (2n)l K∪L

.

∑ a∑ ∑

Therefore,

µ(K ∪ L) ≤

∑ a∑ ∑ 1

α (2n)l K∪L

K⊆N\A

K⊆N\A

a∑

p=0,

p even

p=0,

p even

L⊆A,

l=a−p−1

L⊆A,

l=a−p−1

K⊆N\A

p=0,

p even

1

α (2n)m−1 = 1 α (2)n−1 (2n) m−1 .

L⊆A,

l=a−p−1

Moreover, we have 1 α (2)n−1 (2n) m−1 = 2n−1 (2n) m−1

(2n) n (2n) m = 2 n−1 (2n) m−1

2(2) n−1 (n) n (2n)(2n) m−1

= 1 < 1 = µ(N).

4nn+1 [ ∑

Hence we have µ(N) >

[ ∑

µ(N) −

K⊆N\A

a∑

p=0,

p even

L⊆A,

l=a−p−1

K⊆N\A

a∑

p=0,

p even

L⊆A,

l=a−p−1

]

µ(K ∪ L) > 0.

]

µ(K ∪ L) , i.e.,

We can therefore conclude that (n − a + 1)! × I µ A > 0, i.e., Iµ A > 0.

The following lemma gives a simplified condition of previous condition

not(a S T C I∪M a N ) for all S N.

Lemma 2. The previous condition [not(a S T C I∪M a N ) for all S N] is equivalent at

[

not(aN\{i} T C I∪M a N ) for all i ∈ N ] .

17

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