Figure 1. A potential computation tree \(\mathcal{T}^N_{C_0(x)}\) for a non-deterministic Turing machine \(N\) starting from the initial configuration \(C_0(x)\). Accepting states are labeled \(\odot\) and rejecting states \(\circ\). Note that although this tree contains an accepting computation sequence of length 4, its maximum depth of 5 still counts towards the determination of \(time_N(n) = \max \{\text{depth}(\mathcal{T}^N_{C_0(x)})\ :\ \lvert x\rvert = n\)}.