of each qubit, for all alternative influence-pasts, i.e. this is not a string of $N$ measurement angles $\delta_i$ but of $\sum_{i=1}^N|P_i|$ measurement angles of the form $\delta_i(c_i)$, where we have $|P_i|$ angles per qubit.

In UBQC, the server is not forced to follow the instructions and the client cannot verify if the computation is done correctly. One can modify the protocol to allow for such verification (see Theorem \[vbqc verif\]), as was first done in [@fk]. The central idea is to include trap qubits at positions unknown to the server. The client can send states from $\{\ket{0},\ket{1}\}$ (called dummies), which have the effect of breaking the graph at this vertex, removing it along with any attached edges. This can be used to generate isolated qubits in the graph in a way that is undetectable by the server. These isolated qubits do not affect the computation while they have deterministic outcome if measured in the correct basis. They can therefore be used as traps: a client can easily detect if one of them has been measured incorrectly but the server is ignorant of their position in the graph. This idea was introduced in [@fk] and later optimised by different protocols, such 