# LDC-E1353 — Bad evaluation mode

## What it means

A case context names the evaluation mode the computation runs in —
advisory, compliance, regulatory, simulation, or audit. The mode is a
single choice from a closed list: it steers how the engine treats the
result, so an unknown or repeated mode cannot stand. The compiler
stops at the axis rather than computing under an assumption policy
nobody declared.

The repair is to name one mode from the list. The default holds when
the axis is absent; when it is present, it must say exactly one thing.

## Example

```run
{"argv": ["lower-case", "$ROOT/case.law"], "files": {"case.law": "language \"law.core\" version \"0.2\";\npackage demo.diagnostics version \"0.1.0\";\nnamespace \"urn:law:demo:diagnostics\";\n\nentity A;\n\ncase Solo {\n    context {\n        legal_time @2026-08-26;\n        mode bogus;\n    }\n}\n"}, "expect": "LDC-E1353"}
```

## Fix

```run
{"argv": ["lower-case", "$ROOT/case.law"], "files": {"case.law": "language \"law.core\" version \"0.2\";\npackage demo.diagnostics version \"0.1.0\";\nnamespace \"urn:law:demo:diagnostics\";\n\nentity A;\n\ncase Solo {\n    context {\n        legal_time @2026-08-26;\n        mode advisory;\n    }\n}\n"}, "expect": null}
```

## Engine message

The engine reports this in its own wording:

```text
$ROOT/case.law:10:9: error LDC-E1353: mode axis §168.2: value is a §171 evaluation mode from the list advisory, compliance, regulatory, simulation, audit
```

## Related

- [LDC-E1332](/diagnostics/LDC-E1332/) — a policy axis in an unresolvable shape.
- [Time](/constructs/time/) — the legal time a case runs at.