Try it yourself

Check a walker back in

Runs in your browser: app code, no model.

An illustration of the same rules in a second setting: a folding walker back at a loan closet, with a made-up loan record and an illustrative $65 deposit. No closet, pilot or partner is behind it. It only checks that the parts came back.

DETERMINISTIC · app code, no model

Parts seen in the tray · illustrative prices

$0 seen of the $65 deposit (illustrative)

0 of 5 parts clear on the loan record

HELD

Stays off the shelf until a volunteer looks. A hold is not a charge (clause 5.1).

Walker frame MISSING · HELD
Rubber tip, rear left MISSING · HELD
Rubber tip, rear right MISSING · HELD
Glide, front left MISSING · HELD
Glide, front right MISSING · HELD

A loan closet · folding walker · illustration · RET-PLAY

The bench, seen from above

Tap “To tray” or drag an item. Keyboard: Enter or Space moves it, Arrow Right to the tray, Arrow Left back to the box.

The open box5 inside

Inspected tray0 of 5 counted

Nothing counted yet. An item counts once it settles here.

Try a case

Make it tricky another closet's walker, an unreadable tag

Leaving an item in the box is the first trick. These are the others the engine knows about.

Walker frameAnother closet's walker (asset tag LC-WF-0388)Asset tag can't be read

[Illustration · same engine, made-up loan record and prices; no closet, pilot or partner]

What the engine decides

DETERMINISTIC · app code, no model

Packing slip versus what is in the tray, per line, with the engine's status and reason
Packing slip	Tray	Status	Reason
Walker frame $45 · LC-WF-0417	0/1	MISSING	0 of 1 seen in the tray on this bench
Rubber tip, rear left $4	0/1	MISSING	0 of 1 seen in the tray on this bench
Rubber tip, rear right $4	0/1	MISSING	0 of 1 seen in the tray on this bench
Glide, front left $6	0/1	MISSING	0 of 1 seen in the tray on this bench
Glide, front right $6	0/1	MISSING	0 of 1 seen in the tray on this bench

Ready to re-lend · deposit back · clause 4.2$65Not on a held box, unless a person writes an override reason.

Deposit less missing parts · clause 4.3—Not offered: no line is clear enough to refund on its own.

Engine recommends Keep it off the shelf, deposit held (clause 4.2). It recommends; it never picks.

CLAUSE 7.1 · NOT A SAFETY CHECK This check records which parts came back. It does not judge whether equipment is safe or suitable for anyone; the closet's own safety check still applies before anything is re-lent.

A person decides

A volunteer signs off every return; a held item never goes back on the shelf by itself.

The counter output the engine read

Your tray, written in the same CountResult shape the bench's tray counter builds from SAM 3.1's tracks. No SAM ran here: you placed the items, and app code read them. Policy illustration-1.

{
  "counts": {
    "walker_frame": 0,
    "tip_rear_left": 0,
    "tip_rear_right": 0,
    "glide_front_left": 0,
    "glide_front_right": 0
  },
  "arrivals": [],
  "flags": []
}

Why the same rules fit a loan closet (illustration)

01 · The problem: Loan closets check returned walkers by eye, with no record. A walker can go back on the shelf without a rubber tip.
02 · The solution: The same rules: count each part into the tray against the loan record, and hold the walker off the shelf if anything is missing.
03 · Why it matters: The person harmed by a miss is the next borrower, often frail or recovering, not a store's margin.
04 · How it’s used: Unpack, read each line, and a volunteer signs it off. The closet's own safety check still comes after; this only checks parts came back.