A function
When evaluated,
Properties
1 & \text{ if } \tau^(p_1) = 0 \text{ or } \tau^{}(p_{2}) = 1\ 0 & \text{ otherwise } \end{cases}$$
1 & \text{ if } \tau^(p_1) = \tau^{}(p_{2})\ 0 & \text{ otherwise } \end{cases}$$
A function τ∗:F→{0,1}
When evaluated, τ∗(x)=τ(x)
1 & \text{ if } \tau^(p_1) = 0 \text{ or } \tau^{}(p_{2}) = 1\ 0 & \text{ otherwise } \end{cases}$$
1 & \text{ if } \tau^(p_1) = \tau^{}(p_{2})\ 0 & \text{ otherwise } \end{cases}$$