1<σ<0.51<\sigma<0.51<σ<0.5
−1<σ<0.5-1<\sigma<0.5−1<σ<0.5
−1<σ<1-1<\sigma<1−1<σ<1
−1<σ<−0.5-1<\sigma<-0.5−1<σ<−0.5
