RETURN-B2: the return specification for the stage B2 pilot

Frozen with the stage file. The packet builder serves it, the brief cites it, and the validator's schema is read from it.

Rule 0, in the contract's words

Rule 0. Single placement, exception on the record. A second-order theme carries one third-order theme: the one whose gate its material satisfies best; where more than one gate is satisfied, the theme's decide_when_both field decides. A second placement only where one cannot carry the material, and never silently: it needs its own distinct supporting concept, a written why_not_one in terms of what the single placement would fail to carry, a named dispensable one, and a line in multiplacement_log.jsonl. Three at most; beyond three, place one and record item-is-a-bag. An unjustified extra is a defect. The log is a measurement: recurring (primary, additional) pairs are boundaries the scheme has not drawn, and stage C1 reads that table first.

What you return

One JSON line per item in the packet, in packet order, and nothing else between the lines. Read the index page whole first. Open a family's page before you place anything into it, and list the families you opened in families_opened.

• sub, theme_id: the item's heading, <sub>/<theme_id>, copied exactly: the room's name, then the item's id (T2- and five digits, such as T2-08479).
• batch: the packet name (the name on the packet's title line, such as P03-r3-1). agent: your reader id as given to you. replicate: 1. position: the item's number in the packet.
• third_order: the theme ids you place the item on, primary first. One id, unless rule 0's exception holds; never more than three.
• multi: true when third_order holds more than one id.
• why: for each id in third_order, what about THIS item put it there rather than its nearest neighbour.
• confidence: clear or arguable.
• read: whole (you read the label, the note and every concept) or theme-block (the label and note, and the concepts in part).
• exemplar_read: null. No exemplar is served at this stage.
• families_opened: the family ids whose pages you opened for this item.
• t_start, t: when you began and finished the item (ISO time, as you can tell it).
• support: the concept ids your placement rests on, copied exactly from the item's own concept lines (C and seven digits, such as C0781518). Cite only concepts listed under the item you are placing; an id from another item, or one you do not see in the packet, is an error.
• multiplacement_log: null when multi is false. When multi is true, this is the line rule 0 owes to multiplacement_log.jsonl: {"primary": "T3-…", "additional": ["T3-…"], "codes": ["C…"], "why_not_one": "what the single placement would fail to carry", "dispensable": "T3-…"}. The check leg copies it into the pilot's record. It never enters the run's own multiplacement_log.jsonl from stage B1.
• item_is_a_bag: true only when more than three themes would be needed and at least one theme beyond the one placed has three concepts of its own. Then third_order holds one id and why names the others. A bag with no other theme at the three-concept floor is not flagged a bag: item_is_a_bag false, also_present {}.
• also_present: {} unless item_is_a_bag is true. For a bag, the themes beyond the one placed that have at least three concepts of its own, twenty themes at most, each with those concept ids: {"T3-…": ["C…", "C…", "C…"]}. Twenty is a bound, not a goal: name only the themes you find at the floor; you need not reach twenty. A theme with fewer than three concepts of its own is not listed. support holds the concepts behind the placed theme; a theme in also_present never repeats the placed one.

{"sub": "...", "theme_id": "T2-.....", "batch": "P03-r3-1", "agent": "...", "replicate": 1, "position": 23, "third_order": ["T3-007"], "multi": false, "why": {"T3-007": "what about THIS theme put it here rather than its nearest neighbour"}, "confidence": "clear|arguable", "read": "whole|theme-block", "exemplar_read": null, "families_opened": ["G03", "G09"], "t_start": "...", "t": "...", "support": ["C0781518"], "multiplacement_log": null, "item_is_a_bag": false, "also_present": {}}
END-OF-RETURN

After your last line, write the end marker END-OF-RETURN on a line of its own. Confirm that you reached the end of the packet by writing that marker; a return without it is a partial return and is reissued.