> For the complete documentation index, see [llms.txt](https://docs.b2ihealthcare.com/snow-owl-authoring-platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2ihealthcare.com/snow-owl-authoring-platform/browsing-and-searching/semantic-queries/project-explorer-view/expression-file/validation.md).

# Validation

Queries are validated continuously as you enter the expression. Erroneous parts of the expression are indicated with a red wavy underline, as well as a red error marker ![](/files/-M286fKxzkhS0-QC4mw0) on the left margin of the editor.

Expression Constraint Language (ECL) queries are also validated to check for inactive concepts that are referenced in the expression. As the editor only allows the selection or insertion of active concepts through the concept picker, this feature helps in identifying concepts that became inactive after the expression was authored.

![Inactive Reference Warning in ECL Editor](/files/qB5QuM5bm54HXIyCChSQ)


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# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.b2ihealthcare.com/snow-owl-authoring-platform/browsing-and-searching/semantic-queries/project-explorer-view/expression-file/validation.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.