\(\tilde \tau _{1}={\left (\tau _{1}, s_{1}\right)}\) | \(\tilde \tau _{2} = \left ({ \tau _{1},s_{2}}\right)\) | \(\tilde \tau _{3} = \left ({ \tau _{2}, s_{1}}\right)\) | \(\tilde \tau _{4} = \left ({ \tau _{2},s_{2}}\right)\) | |
---|---|---|---|---|
z 1 | × | ✓ | × | ✓ |
z 2 | ✓ | × | ✓ | × |
z 3 | × | ✓ | × | ✓ |
z 4 | ✓ | × | ✓ | × |