b) Using QBCR2: Similarly as for QBCR1, qm(A) = L1 is transferred to A ∩ D¯ ; also qm(C) = L1 and qm(C ∪ D) = L1 are transferred to C ∩ D¯. But now, differently, qm(D) = L2 **is equally split to the**
focal elements of D¯, but only C ∩ D¯ is focal for D¯ , so C ∩ D¯ **receives the whole qualitative mass of**
D**. Finally we get:**
qmQBCR2(A ∩ D¯ |D¯ ) = L1 qmQBCR2(C ∩ D¯ |D¯ ) = qm(C ∩ D¯ ) + qm(C) + qm(C ∪ D) + qm(D) = L1 + L1 + L1 + L2 = L5 All others are equal to L0**. The resulting qualitative conditioned mass is quasi-normalized since** L1 + L5 = L6 = Lmax.

The results obtained by QBCR1 and QBCR2 are coherent with rational human reasoning since after bombing zone D we get, in such case, a higher belief in finding enemies in C ∩ D¯ than in A ∩ D¯ **which**
is normal due to the prior information we had before bombing D**. QBRC2 is more specific than QBRC1.** Say differently, QBRC1 is more prudent than QBRC2 in the revision of the masses of belief.

## - **Case 2**: D¯ = A ∪ B ∪ C.

a) Using QBCR1: qm(C ∪ D) = L1 is transferred to C since C **is the largest element (with respect to**
inclusion) from A∪B ∪C which is included in C ∪D. qm(C ∩D¯ ) = qm(C) since C ∩(A∪B ∪C) = C.

qm(D) = L2 is transferred to A ∪ B ∪ C since no element from A ∪ B ∪ C is included in D**, so the** qualitative mass of D **becomes** zero (i.e. it takes the linguistic value L0**). Thus we finally obtain:**
qmQBCR1(A|D¯ ) = L1 qmQBCR1(C|D¯ ) = qm(C) + qm(C ∪ D) + qm(C ∩ D**¯) =** L1 + L1 + L1 = L3 qmQBCR1(A ∪ B ∪ C|D¯ ) = L2

All others are equal to L0**. The resulting qualitative conditioned mass is quasi-normalized since** L1 + L3 + L2 = L6 = Lmax.

b) Using QBCR2: qm(C ∪ D) = L1 and qm(C ∩ D¯ ) = L1 **are similarly as in QBRC1 transferred to** C.

But qm(D) = L2 is equally split among the focal qualitative elements of D¯ = A ∪ B ∪ C**, which are**
A and C, so each of them receive 1/2 · L2 = L2/2 = L1**. Whence**
qmQBCR2(A|D¯ ) = qm(A) + 12 qm(D) = L1 +
1 2 L2 = L1 + L1 = L2 qmQBCR1(C|D¯) = [qm(C) + qm(C ∪ D) + qm(C ∩ D¯ **)] +** 12 qm(D) = [L1 + L1 + L1] + L1 = L4 All others are equal to L0**. The resulting qualitative conditioned mass is quasi-normalized since**
L2 + L4 = L6 = Lmax.

The results obtained by QBCR1 and QBCR2 are again coherent with rational human reasoning since after bombing zone D we get, in such case, a higher belief in finding enemies in C than in A **which is normal** due to the prior information we had before bombing D **and taking into account the constraint of the model.**

## 7 Conclusions

In this paper, we have designed two Qualitative Belief Conditioning Rules in order to revise qualitative basic belief assignments and we presented some examples to show how they work. QBCR1 is more prudent than QBCR2 because the revision of the belief is done in a less specific transfer than for QBCR2. We use it