Manuscript Oai212-A@1 · Oai212-A.tex · lemma · 79323841
Lemma: Timer arrivals are undirected first-passage times
Bridge 1: an exact controlled operator-spreading model › The local timer rule · lines 549–578 · proof included or linked
Oai212-A@1#lem:timers
For every positive timer realization, the flagging time of in Specification spec:cnot equals . The successful edges form a rooted tree. For independent continuous timers, ties occur with probability zero.
Proof. A successful edge flags at time , so the successful ancestry chain gives a path of cost . Thus .
Conversely, suppose a vertex of minimum among those not yet flagged should have been reached earlier. On a minimizing path, let be the first edge crossing from flagged to unflagged vertices. Its timer began when was flagged. Since at that stage of the induction, it expires no later than the path's proposed arrival at . If the operation was cancelled, was already flagged earlier; otherwise it flags . Both contradict the supposed delay. Induction over the finite graph proves equality.
Each non-root vertex is targeted exactly once, by an already flagged vertex. Arrival times strictly increase along successful edges, so there is no directed cycle. Continuous independent weights make distinct simple-path sums unequal almost surely: condition on an edge present in only one of the two paths. There are only finitely many simple paths in the finite graph.