OptionalabsenceTrue when this leaf represents MISSING evidence (an exposure/gap): the trace bottoms out in the absence of proof, not in proof.
Depth from the root (0 = the thing being explained).
OptionaldetailOptional secondary line (a rating, a driver, a relevance).
Graph node / action id this hop refers to.
Short title shown on the hop.
OptionalleafTrue when this hop is a leaf (raw evidence or documented absence).
OptionalparentParent hop id (for tree reconstruction); absent on the root.
Tier label, e.g. "action" | "analytic" | "meaning" | "raw". Free text so the component is not tied to a fixed tier vocabulary.
One node in a provenance trail.