Wat is Label concurrency, average uniqueness?

Label $i$ spans the bars $(t_{0,i}, t_{1,i}]$. The label concurrency $c_t$ of bar $t$ is the number of labels whose span contains it. The average uniqueness of label $i$ is $\bar u_i = \frac{1}{t_{1,i} - t_{0,i}}\sum_{t\in(t_{0,i}, t_{1,i}]}1/c_t$: the share of its information it holds alone.