−1<r<1-1<r<1−1<r<1
−1>r>1-1>r>1−1>r>1
−1≤r≤1-1 \leq r \leq 1−1≤r≤1
−1≥r≥1-1 \geq \mathbf{r} \geq 1−1≥r≥1
