P x i x j 0

P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0. P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0. P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0. P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0
P x i x j 0