# Alignment and concept bridges

Different editions, languages, and upstream sources describe the same ideas
in different words. Alignment records those correspondences explicitly —
without ever merging meanings by assumption. One revision in two languages
is two editions with a declared correspondence, never one shared meaning.

Confirmation marks in parentheses, such as (S) or (I), follow the
[legend on the topic index](/corpus/#how-this-topic-marks-confidence).

## A worked mapping: the renamed holding link

The lab tour renames the shared holding relation between two fixture
states: `owns` in `labparcels.iface` at `0.1.0` becomes `holds` at
`0.2.0`, with parameters, kind, key, and label unchanged. The compiler
treats those as two different nodes — a relation pin is not executed,
so no annotation carries the old identity across. Saying "holds
continues owns" is therefore a human-authored mapping, and a useful
one only spells out its direction, its preserved conditions, and its
status:

- **Direction.** Old revision to new revision: rows recorded under
  `owns` read as rows under `holds`. The reverse is not claimed —
  nothing promises the old consumers accept the new name.
- **Preserved conditions.** Same parameter shapes (`Owner`, `Parcel`),
  same kind (`institutional`), same key (`parcel`), same label text.
  Any later change to one side reopens the mapping.
- **Status.** `review` while a second author checks the claim,
  `accepted` once recorded, `revoked` if the meanings drift apart.
  Revocation deletes no rows; it withdraws the permission to read
  across.

The report schema for the narrow profiles draws the decisive boundary
for exactly this shape: a decision carries `interpretation_basis`
`declared_mapping_assumption`, keeps `all_source_conditions_retained`
true, and keeps `semantic_equivalence_proved` false — see the
[report format](/protocols/schemas/concept-rule-alignment-report/).
The mapping below follows that shape as a team-kept illustration
**(T)**; no checkout command produces this report for the parcels
fixtures, whose profiles cover other pairs of systems:

```json
{
  "source": "labparcels.iface@0.1.0 owns",
  "target": "labparcels.iface@0.2.0 holds",
  "direction": "source_to_target_under_interpretation",
  "status": "accepted",
  "conditions": {
    "interpretation_basis": "declared_mapping_assumption",
    "all_source_conditions_retained": true,
    "semantic_equivalence_proved": false
  }
}
```

Read the last line as the whole point: the record proves that a
reviewed human said "these correspond under these conditions", never
that the two nodes mean the same thing.

## The align declaration

The grammar offers an edition-level correspondence block between two
references, with a relation name, a free-text status, and a reviewer:

```text
alignment_decl          = "align", reference, "with", reference, "{",
                            { alignment_item },
                          "}" ;
alignment_item          = "relation", qualified_name, ";"
                        | "status", identifier, ";"
                        | "reviewer", expression, ";"
                        | metadata_item ;
```

The declaration is metadata only: it is stored on the document, never
lowered into formulas or evidence. Status values are a per-package team
convention, not a closed vocabulary. Four maturity facts, kept in sync
with the vocabulary bridge notes: the declaration is supported grammar
and compiles in real packages **(S)**; no structural query reads align
rows back — the links question covers five other link kinds **(S)**;
adoption is broad, with over two thousand blocks across dozens of
source files observed in the corpus **(S)**; and the semantic effect
is nil **(S)**.

## Manual alignment packages

For dictionary-scale correspondence, the established pattern is an ordinary
package that maps shared vocabularies to outside records, handwritten and
reviewed like any other corpus content. The reference example,
`arxo.jurisdiction_alignment`, maps the currency, geography, country, and
courts dictionaries to their outside records. A generic composition
mechanism was considered for this job and rejected in favor of explicit
packages. This is a **team convention** (T).

Shared dictionaries themselves (`vocab.geo` and its siblings) stay
types-plus-constants packages with no rules and no sources, which is what
makes them safe mapping endpoints. **(S)**

## The concept catalog

The concept catalog is a derived full-text index over compiled packages and
import snapshots. It answers "which packages talk about this idea" and never
merges semantics: a catalog hit is a pointer for a human or a policy to
follow up, not an identity claim. Observed tool surface:

```text
$ python3 corpus/tools/concepts/catalog.py --help
usage: catalog.py [-h] --db DB {build,search,show,candidates} ...
Derived concept catalogue: pinned package/Import IR views, never a semantic
merger.
```

Build the index from pinned inputs, then search, show, or list candidates
from the database file. The catalog tool **requires a source checkout**
(I): it lives in the repository, not in the public release.

A worked route over the lab fixtures: an author needs a parcel
concept for a new package and checks the catalog before minting one.
The inputs are pinned in a manifest — two compiled dependency
snapshots, nothing else:

```json fixture="catalog-mini/manifest.json"
{
  "format": "arxo.concept-catalog.inputs/0.1",
  "packages": ["../parcels-fees/deps/*.lawir.json"],
  "imports": []
}
```

Build the index, then search for the idea:

```text
$ python3 corpus/tools/concepts/catalog.py --db /tmp/lab-work/catalog-route.db build docs/corpus/lab/fixtures/catalog-mini/manifest.json
{"concepts":13,"indexed":2,"removed":0,"reused":0,"sources":2}
$ python3 corpus/tools/concepts/catalog.py --db /tmp/lab-work/catalog-route.db search parcel | python3 -c "import json,sys; [print(r['concept']['native_id'],'|',r['concept']['project']) for r in json.load(sys.stdin)]"
urn:law:lab:parcels:iface#Parcel | labparcels.iface
urn:law:lab:parcels:registry#Parcel | labparcels.registry
urn:law:lab:parcels:registry#ParcelKind | labparcels.registry
urn:law:lab:parcels:iface#Owner | labparcels.iface
urn:law:lab:parcels:registry#registered | labparcels.registry
urn:law:lab:parcels:iface#owns | labparcels.iface
urn:law:lab:parcels:iface#ParcelKind | labparcels.iface
urn:law:lab:parcels:registry#kind_of | labparcels.registry
urn:law:lab:parcels:registry#transfer_request | labparcels.registry
```

Nine hits across two packages. Inspect the canonical-looking one:

```text
$ python3 corpus/tools/concepts/catalog.py --db /tmp/lab-work/catalog-route.db show 'urn:law:lab:parcels:iface#Parcel' | python3 -c "import json,sys; d=json.load(sys.stdin); print(d['name'],'|',d['family'],'|',d['native_id']); print('visibility:',d['raw']['visibility'],'| project:',d['project']); print('labels:',[l['text'] for l in d['labels']])"
Parcel | type | urn:law:lab:parcels:iface#Parcel
visibility: public | project: labparcels.iface
labels: ['registered parcel']
```

A public entity type with a matching label — a reuse candidate. Ask
the catalog for correspondence candidates before deciding:

```text
$ python3 corpus/tools/concepts/catalog.py --db /tmp/lab-work/catalog-route.db candidates 'urn:law:lab:parcels:iface#Parcel' | python3 -c "import json,sys; d=json.load(sys.stdin); print('automatic_acceptance:',d['automatic_acceptance'],'| scope:',d['scope']); [print(c['target']['native_id'],'|',c['status'],'| score',c['score'],'|',','.join(c['reasons']),'| failures:',','.join(c['checks']['failures']) or 'none') for c in d['candidates']]" | head -3; echo ...
automatic_acceptance: False | scope: bounded identifier/label/signature retrieval; no equivalence proof
urn:law:lab:parcels:iface#Owner | candidate | score 5 | lexical_overlap | failures: none
urn:law:lab:parcels:registry#Parcel | incompatible | score 45 | lexical_overlap,same_label | failures: different_type_kind
...
```

Eight further rows follow, all `incompatible` (the full JSON also
carries `pending: semantic_correspondence_requires_review` on every
row). No automatic acceptance — and read the top-scoring row
carefully: `registry#Parcel` is refused as a correspondence
endpoint with `different_type_kind`, but that is a matcher
limitation, not a verdict of different concepts. The matcher only
compares declaration kinds (entity versus alias) and never follows
the alias target; the compiled node itself says where it points:

```text
$ python3 -c "import json; d=json.load(open('fixtures/parcels-fees/deps/labparcels.registry.lawir.json')); n=next(n for n in d['nodes'] if n.get('name')=='Parcel'); print(n['typeKind'], '->', n['target']['name'])"
alias -> labparcels.iface#Parcel
```

`registry#Parcel` is a direct alias for the shared `iface::Parcel`
— same concept, re-exported spelling. The reuse decision is the
author's, and here it is to reuse: import `labparcels.iface` at
its pinned version and reference its public `Parcel`, instead of
minting a third parcel type. The catalog row stays a pointer; the
decision lives in the new package's import pins.

## Narrow alignment profiles

A few bespoke bridges map specific outside systems into corpus form. Each is
a hand-registered module for one pair of systems — physics units against a
public unit ontology, order theory against two proof assistants — plus a
positive-rules helper. Observed modules:

```text
$ ls corpus/tools/concepts/alignment_profiles/
__pycache__
isabelle_orders.py
lean_orders.py
lean_stacks.py
physics.py
positive_rules.py
```

Each profile ships its own policy and report formats, and the full-profile
checks verify source links, replay, revocation, and impact. These are narrow
experimental bridges, not a general mapping framework: adding a new pair
means authoring a new module with its own policy. **Experimental** (X).

## What to read next

- [LawQL reference](/lawql/) for the structural relations that alignment
  tooling queries.
- [Schema catalog](/protocols/schemas/) for the alignment policy and report
  formats.
- [MCP tools](/guide/mcp-tools/) for catalog-style discovery from clients.