In the harness execution kernel dynamics, into which two disjoint sets is the action module emission space $\mathcal{A}$ partitioned?

When an emitted action $e_t$ belongs to the set of executable calls $\mathcal{U}$, the execution kernel evaluates it using the capability registry to produce $o_t = \text{Exec}(e_t; C_t)$.

What are the two conditions under which the closed-loop rollout trajectory terminates?

Explain the step-by-step history initialization and concatenation update mechanism for trajectory $\xi$ throughout a harness execution rollout.

Match each formal symbol from the rollout and kernel dynamics to its definition.

Place the following events of an execution step $t$ in their correct chronological order according to harness kernel dynamics.

Explain why the rollout terminates at step 10, what observation $o_{10}$ is recorded, and how this termination differs from normal task completion.