> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/snomed-ct-specifications/snomed-ct-expression-constraint-language/appendices/appendix-b-examples-of-invalid-expressions/b5-exclusion-and-not-equals-invalid-expressions.md).

# Exclusion and Not Equals - Invalid

<table data-full-width="true"><thead><tr><th>Invalid Expression Constraint</th><th>Precoordinated</th><th>Postcoordinated</th></tr></thead><tbody><tr><td>&#x3C;&#x3C; 19829001 | Disorder of lung| MINUS &#x3C;&#x3C; 301867009 | Edema of trunk|</td><td>27719009 | Acute gastrointestinal hemorrhage| 19242006 | Pulmonary edema|</td><td>19829001 | Disorder of lung| : { 116676008 | Associated morphology| = 40829002 | Acute edema| , 363698007 | Finding site| = 22943007 | Trunk structure| }</td></tr><tr><td>&#x3C;&#x3C; 19829001 | Disorder of lung| MINUS ^ 700043003 | Example problem list concepts reference set|</td><td>67599009 | Pulmonary congestion|</td><td>67599009 | Pulmonary congestion| : 363698007 | Finding site| = 3341006 | Right lung structure|</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : 116676008 | Associated morphology| = ((&#x3C;&#x3C; 56208002 | Ulcer| AND &#x3C;&#x3C; 50960005 | Hemorrhage| ) MINUS &#x3C;&#x3C; 26036001 | Obstruction| )</td><td>397825006 | Gastric ulcer| 235670001 | Gastric stomal obstruction|</td><td>64572001 | Disease| : 116676008 | Associated morphology| = 26036001 | Obstruction|</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : 116676008 | Associated morphology| != &#x3C;&#x3C; 26036001 | Obstruction|</td><td>81060008 | Intestinal obstruction| 56265001 | Heart disease|</td><td>64572001 | Disease| : 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach|</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : [0..0] 116676008 | Associated morphology| = &#x3C;&#x3C; 26036001 | Obstruction|</td><td>81060008 | Intestinal obstruction| 234059001 | Venous stenosis|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| } { 116676008 | Associated morphology| = 45771005 | Acute bleeding ulcer| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| }</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : [0..0] 116676008 | Associated morphology| != &#x3C;&#x3C; 26036001 | Obstruction|</td><td>196652006 | Acute duodenal ulcer| 8377001 | Hernia, with obstruction|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| } { 116676008 | Associated morphology| = 45771005 | Acute bleeding ulcer| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| }</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : [0..0] 116676008 | Associated morphology| != &#x3C;&#x3C; 26036001 | Obstruction| AND [1..*] 116676008 | Associated morphology| = &#x3C;&#x3C; 26036001 | Obstruction|</td><td>196652006 | Acute duodenal ulcer| 8377001 | Hernia, with obstruction| 56265001 | Heart disease|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| } { 116676008 | Associated morphology| = 45771005 | Acute bleeding ulcer| , 363698007 | Finding site| = 422897007 | Vascular structure of stomach| }</td></tr></tbody></table>

<a href="https://docs.google.com/forms/d/e/1FAIpQLScTmbZIf0UEQwYDkY27EEWBkaiYkHSbR0_9DmFrMLXoQLyL7Q/viewform?usp=pp_url&#x26;entry.1767247133=ECL+Specification&#x26;entry.670899847=Exclusion%20and%20Not%20Equals%20-%20Invalid" class="button primary">Provide Feedback</a>


---

# 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.snomed.org/snomed-ct-specifications/snomed-ct-expression-constraint-language/appendices/appendix-b-examples-of-invalid-expressions/b5-exclusion-and-not-equals-invalid-expressions.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.