Exact potential summand
The part of an additive route score that depends only on endpoints.
Role. Target. Graph node exact.
If every state is reachable from a fixed start, path worth depends only on the final state exactly when r is an exact potential: each edge scores the utility of its target minus the utility of its source.
— Frames relations note
If an edge score is a gradient of a state potential, every closed walk sums to zero. That is why state utility and cycle residue conflict on round trips: see the red edge in Lean (stateCycleIncompat).
Exactness is a representation fact about a particular reward, not a claim that endpoints were the intended moral object.