Read answers

An answer from an executable model is a document, not a sentence: the outcome, the rules that fired, diagnostics on what blocked a derivation, source addresses, legal time and hashes. This page is the single reference for reading it, including the status table other pages link to. The Guide pages on silence and explain and doubt cover the user’s side.

Keep the raw answer

Never flatten an answer to a boolean. Store the untouched response under the question that produced it, then derive views: a later step may need a field this one ignores, and reproduction needs the hashes as received.

TypeScript

type RawAnswer = {
  bytes: Uint8Array;        // untouched response, kept for replay
  callOk: boolean;          // transport and call shape accepted
  evaluationStatus: string; // see the table below
  truthStatus?: string;     // TRUE_ONLY | FALSE_ONLY | BOTH | NEITHER
  value?: unknown;          // kind-specific payload
  whyNot?: unknown;         // absent, [] or a blocker list: three different facts
  issues?: unknown[];       // engine messages, kept verbatim
  provenance?: unknown;     // rules, sources, hashes, legal time
};

Status: labeled pseudocode. Not executed; it defines no contract beyond the prose.

The three axes

Read every answer on three axes, in order, and never merge them.

Axis	Field	Question
Call	error flag, exception, refusal	did the call itself go through
Evaluation	evaluationStatus	did the engine finish the computation, and if not, why
Result	truthStatus, value, positions	what the finished computation establishes

• COMPUTED is not a positive result. It says the computation finished; a computed answer can still support neither side.
• A refused call is not NEITHER. Fix the call (predicate name, arity, types, project) instead of reading silence into it.

Refusal shape from the local CLI, run from a directory without a case project:

Output

law: REFUSAL LPK-E0201: no law.toml here or above — pass the project via --project

Status: ran locally in an earlier authoring session (law ask); not re-run for this page.

Evaluation status

The full set defined by the specification and the published SDK types. Read it before the truth status or values.

evaluationStatus	Meaning	Allowed next step
COMPUTED	the evaluation finished	read the result axis
MISSING_INPUT	a required input snapshot (for example a calendar) or function input was not supplied or is invalid	supply the named input; do not invent it
MISSING_POLICY	a required policy (for example a deadline policy) is not set or is unusable	ask the human or the integrator which policy applies
REQUIRES_JUDGMENT	the canon routes an element to an authority’s judgment	stop; record a human judgment (see Human decisions)
INTERPRETATION_REQUIRED	a disputed reading must be chosen	show the readings the canon names; a human selects one
NON_EXECUTABLE	the needed part of the model cannot run (opaque term, unknown function, non-exhaustive match, unstratifiable negation)	report it; this is a model limit, not a case fact
EXTERNAL_UNAVAILABLE	an external value or its snapshot is missing	supply the snapshot or report the gap
SOURCE_RESOLUTION_FAILED	a source or edition could not be resolved	check the pin and edition (see Pin context)
PRIORITY_CONFLICT	a priority cycle arose in context; no tie-break is made	report the conflict group
UNRESOLVED_NORMATIVE_CONFLICT	two incompatible positions stand with no priority between them	show both; never pick one
CONFLICTED_INPUTS	accepted inputs conflict and the package’s policy says halt; absent that policy this status does not arise	correct the inputs
TYPE_ERROR	a term failed on types, currency, dimension or date/instant mismatch	fix the submitted values or report the model defect
RUNTIME_ERROR	any other evaluation error	report the issue verbatim
RESOURCE_LIMIT	a limit stopped the computation	narrow the question or raise the limit, then re-ask

Precedence and scope, as the specification states them:

• A truth or why-not NEITHER caused by a candidate rule’s failed term names that failure. With several codes the order is MISSING_INPUT, MISSING_POLICY, NON_EXECUTABLE, EXTERNAL_UNAVAILABLE, TYPE_ERROR, RUNTIME_ERROR, RESOURCE_LIMIT. INTERPRETATION_REQUIRED, UNRESOLVED_NORMATIVE_CONFLICT and REQUIRES_JUDGMENT rank above term failures.
• INTERPRETATION_REQUIRED belongs to a result, not the document: an independent question in the same case stays COMPUTED.
• A dated parameter with no value on the date is the law’s own silence: the result stays COMPUTED with a warning issue.
• For collect and positions a candidate’s term failure need not surface as the status. Read issues too.

Observed: with the deadline policy left out, a collect over the German Civil Code periods canon returned NON_EXECUTABLE, an empty value, empty missingInputs, and an error issue coded MISSING_POLICY:

Output

evaluationStatus: NON_EXECUTABLE   value: []   missingInputs: []
issue MISSING_POLICY (error): rule urn:de:corpus:clir:bgb-fristen#TagesfristEnde:
head computation — urn:de:corpus:clir:bgb-fristen#frist_ende.arg1: deadline:
DeadlinePolicy is set neither by request nor by context/profile (SPEC §86)

Status: ran locally (@arxo/law 0.3.3, de.bgb.fristen@0.1.0), 2026-10-04; the run also carried two CONTEXT_FIELD_DEFAULTED warnings. Route on the issue code, and never show the empty value as “no deadline”.

Truth status, NEITHER and silence

For a proposition the engine keeps a pair: is there an accepted positive support, is there an accepted negative one.

truthStatus	Positive support	Negative support	Reading
TRUE_ONLY	yes	no	established
FALSE_ONLY	no	yes	the opposite is established
BOTH	yes	yes	both derived; show both proof lines
NEITHER	no	no	nothing derived either way

NEITHER is neither “false” nor “the law is silent”: the model derived nothing for this question on these facts, and a norm missing from the model is not a norm missing from the law.

Worked example: package kz-labour-code (Labour Code of the Republic of Kazakhstan), predicate feeding_break_too_short, legal time 2026-09-01. A 25-minute break with one child is TRUE_ONLY (resultHash sha256:3e75a474…, shortened). A 30-minute break with one child is NEITHER:

Output

Не установлено ни что «перерыв для кормления ребёнка короче установленного
минимума», ни обратное. Это не утверждение ложности и не заключение о
молчании права: в модели нет вывода ни в одну сторону.

A 30-minute break with two children is TRUE_ONLY again: the one-hour rule for two or more children fires where the thirty-minute rule stays silent. A rule that does not fire proves nothing about the opposite.

Status: ran via the public MCP endpoint (root route), 2026-10-03, all COMPUTED.

Each kind on its own terms

law_ask serves six kinds: truth, collect, calc, deadline, positions, why_not. Each has its own value shape and its own meaning of “empty”; do not read them with one helper.

Collect returns the distinct values satisfying the condition. One can be bound into a later step; several mean none is chosen; none is the absence of a derivation, not zero. Over MCP, break minutes for the known parties returned 25; for unknown parties, a computed empty list:

Output

Значение: пустой перечень: в модели не найдено ни одного подходящего значения.

Status: ran via the public MCP endpoint (root route), 2026-10-03.

Over de.bgb.fristen with the duration left out, collect on frist_ende returned an empty list with COMPUTED, truth returned NEITHER, and missingInputs was empty in both. So an empty, computed collection can still mean “a fact was not given”; the why-not report tells which.

Status: ran locally (@arxo/law 0.3.3, de.bgb.fristen@0.1.0), 2026-10-04.

Calc evaluates an arithmetic tree: (2 + 3) computed to 5 with resultHash sha256:6ce72afd202dacd139e47ca63a6d9db82f2914a7196bd30f6e6dc76feb244f68. An unfinished calc is not a number. Deadline computes on the pinned calendar: 10 calendar days after 2026-09-01 expire on 2026-09-11; without its policy and calendar snapshot it is incomplete.

Status (calc, deadline): ran via the public MCP endpoint (root route), 2026-10-03.

Positions lists normative positions that arose from the facts, each with a modality, a status, a bearer, often a beneficiary, source anchors and the creating rule. The executable modalities are duty, liberty, power and immunity; a prohibition is a duty of forbearance, and other surface forms lower to these four. Show every position with its modality. With the feeding-break facts the answer held two positions of modality duty, status ACTIVE, each with an achievement goal and a window from 2016-01-01.

Status: ran via the public MCP endpoint (root route), 2026-10-03.

An empty positions list does not by itself establish a cause: facts may be missing, the canon may not model the position, a reading may be unselected. Read evaluationStatus and issues before saying why.

Why-not takes the truth question’s shape; its root carries the same statuses, judgment requests and missing inputs as the matching truth question, and its value is the blocker report below.

Missing versus conflicting information

When a derivation is absent, read status, then the diagnostic fields the answer actually has, then the next step they allow. The explanation may be incomplete; do not fill the gap with a guess.

Diagnostic fields

What the answer carries	What it says	Allowed next step
whyNot absent	no report was built (not requested, or not built for this kind)	ask why_not explicitly before explaining
whyNot: []	the report was built and no rule head matches the goal	say the model has no rule for this goal on this pin; check interpretationGated
whyNot with blockers	per-rule conjuncts marked SATISFIED, UNDETERMINED or not satisfied, with continuations	collect the undetermined facts, or stop on a failed guard
whyNotError	building the report failed	report the error; no cause is known
whyNotTermErrors	a candidate rule’s term failed (rule, code, message)	follow the code, as in the status table
interpretationGated	rules for the goal exist but are switched off because their reading is not selected	show the readings; a human selects
missingInputs	input-side requirements (rule, code), such as a missing snapshot	supply them
judgmentRequests	a judgment the canon reserves for an authority	stop for a human judgment
truthStatus: BOTH	both supports derived; not an absence	isolate both derivations
issues	engine messages, including warnings that did not change the status	keep verbatim, route by code

The MCP server attaches a report to a NEITHER truth answer (and to answers over facts with document provenance); the why_not kind always builds one. In the SDK run above, truth held no report and a separate whyNot call built it.

missingInputs is input-side (“not supplied”); blockers are derivation-side (“this conjunct did not hold”). An unsubmitted case fact usually appears only as an undetermined blocker.

The specification names the blocker kinds a why-not graph may show: false body, missing fact, conflicting premise, defeated rule, source not in force, unselected interpretation, missing judgment, unresolved reference. An answer shows some, not necessarily all; undetermined is never false.

Missing facts

Over de.bgb.fristen with the duration left out, the report for frist_ende held two strict, undetermined blockers: TagesfristEnde with one continuation (frist_ereignis satisfied, frist_dauer_tage undetermined) and Verlegung193 with none.

Status: ran locally (@arxo/law 0.3.3, de.bgb.fristen@0.1.0), 2026-10-04.

The same shape over the labour code, with only the child count submitted:

Output

по фактам дела (v3 = 2): тело не определено — фактов не хватает
    ? v2 < 60 — variables are not bound by the goal: v2
    ? child_feeding_break_minutes(urn:kz:tk:employee:1, urn:kz:tk:employer:1, v2)
    ✓ children_under_eighteen_months(urn:kz:tk:employee:1, 2)
    ✓ v3 ≥ 2 — comparison satisfied

Status: ran via MCP in the authoring session on a regional route that has since been retired; not re-run on the root route.

Next step: ask for the undetermined fact (law_rules with contract: true names the inputs). Stop when answered or when the person has no such fact; record it as unknown to the case.

A failed guard

With 30 minutes and one child, the first rule reads both facts and fails only its comparison:

Output

по фактам дела (v2 = 30, v3 = 1): тело не выполнено
    ✓ child_feeding_break_minutes(urn:kz:tk:employee:1, urn:kz:tk:employer:1, 30)
    ✓ children_under_eighteen_months(urn:kz:tk:employee:1, 1)
    ✓ v3 = 1 — comparison satisfied
    ✗ v2 < 30 — comparison not satisfied

Status: as above (retired regional route, authoring session).

Nothing is left to collect, and no rule derives “the break is sufficient”. Pass NEITHER on; re-asking cannot change it.

Exceptions, readings and conflicts

• Defeat. A body holds but a prioritized exception removes the conclusion; the blocker’s strength separates defeasible rules from defeaters. Only facts or a competent decision change it.
• Unselected reading. interpretationGated or INTERPRETATION_REQUIRED: a human chooses, never the agent.
• Both sides. For BOTH, check the case facts for a contradiction first; if they are consistent, report both derivations. Report the two conflict statuses the same way. Never resolve a conflict by preference.

Status: NOT RUN for this page; no defeat, gated reading or BOTH instance was captured. Reproduction: a case satisfying both a rule and its exception; a canon with an interpretation group left unselected; facts satisfying two rules with opposite heads.

Empty search is not absence

An empty search or an empty whyNot says nothing about the act’s text. Never conclude “the norm was never formalized”: search ranks by similarity, and the rule may sit under another predicate, package or unselected reading. Say what was searched on which pin; see Empty search results.

Issues and limits

Keep engine messages verbatim and route by code and severity. Over the measurement-uncertainty example case, a computation stopped on a type error while the unfinished record showed an empty collection:

Output

Вычисление прервано ошибкой типов.
Запись незавершённого результата (это не окончательный ответ): Значение:
пустой перечень: в модели не найдено ни одного подходящего значения.

## Сообщения движка

- Ошибка `TYPE_ERROR`: rule urn:jcgm:clir:gum#CombinedStandardUncertainty:
head computation — sqrt_bounds: the argument is Integer, Decimal or Rational,
got number — связанных узлов: 1.

Status: ran locally in an earlier authoring session (law ask in the example project); not re-run.

An unfinished record is not the answer; passing its values on reports a crash as a finding. A why-not blocker lists at most eight continuations per rule and sets truncated: true when it cut any; stop claims at every limit marker.

Sources, proofs and hashes

“Established” is always relative to a support, and four supports answer four questions.

What the text says. law_sources with a fragment from a rule’s anchors returns an excerpt, language, status and the hash of the full pinned source:

Output

urn:kz:corpus:clir:labour-code#TK_ART82 (article/82, ru-KZ/official), выдержка:
    Статья 82. Внутрисменные и специальные перерывы
1. На отдельных видах работ работникам предоставляются внутрисменные
перерывы, обусловленные технологией и организацией производства и труда,
которые включаются в рабочее время. ...
     hash полного источника: sha256:b9fc7d308b57c2a0ffa7f47de7686115432c77c6247e68f03aaa5b98272c2be6

Status: ran via MCP in the authoring session on the retired regional route; not re-run.

An anchor is an address, not proof that the rule renders the text faithfully. Match is not derivation; the search tool says so on every call:

Output

Это кандидаты ПОИСКА, не ответ права: сходство текста не устанавливает
ни факта, ни нормы.

Status: ran via MCP in the authoring session (top score 0.4027); not re-run.

What derives it. Ask with proof: true to get the evaluation document with its proof graph. law_explain takes that document, or the question with resultHash and codeHash for a verified recomputation, and returns the rule-to-premises chain with a fingerprint a repeat must reproduce. law_inspect reads a saved document without recomputing: hash checks, slices by query, rule, position or node, and diffs.

Status: parameter set of law_explain read from the live tool list, 2026-10-03; NOT RUN as calls. Reproduction: ask the feeding-break question with proof: true and pass the result to both tools.

Will it stand. law_argue returns one of four classes: unassailable, merely defensible, rejected, no arguments. Read it with the skipped-rules list: the dispute profile covers less of the language, so “no arguments” with the decisive rule skipped means robustness was not measured. On a cap refusal raise limits.maxArguments; report a merge refusal verbatim:

Output

мир не слить: пакет "calc-obligations" объявляет семантику 0.2.2, остальные — 0.2.4

Status: ran via MCP on the retired regional route; refused twice before analysis.

Support	Question	Tool	Failure looks like
Derivability	does the engine derive it	law_ask with proof	silence with its diagnostics
Admissibility	is the evidence admitted	the package’s evidence policy	unadmitted or refuted support
Robustness	does it stand in dispute	law_argue with limits	rejected, or unmeasured when decisive rules were skipped
Fidelity	does the model render the source	human review via a mismatch report	a filed report, not a derived value

For protected predicates admission controls derivation: a rejected support grounds nothing (see Collect facts and evidence). Robustness reads derivation’s output, not the world. Fidelity conditions all three; a suspected mismatch goes to a report naming the package, fragment or predicate and the answer’s call id.

Validation record

Show commands, versions and results

Check	Where	Result
Status set (14 values)	specification; @arxo/law-types 0.3.3 EvaluationDocumentEvaluationStatus	identical
whyNot / whyNotError / interpretationGated semantics	MCP server source, read 2026-10-04	as described
Feeding-break truth, collect, calc, deadline, positions, why-not	public MCP endpoint, root route, 2026-10-03	as quoted
BGB empty collect, NEITHER, blockers, NON_EXECUTABLE with MISSING_POLICY	@arxo/law 0.3.3, de.bgb.fristen@0.1.0, 2026-10-04	as described
Blocker shapes, source excerpt, search notice, argue refusal	MCP, authoring session, retired regional route	carried over, not re-run
Type-error record, CLI refusal	local CLI, authoring session	carried over, not re-run
Eight-continuation cap	specification only	not observed live

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