> 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-a-examples-of-valid-expressions/a5-exclusion-and-not-equals-valid-expressions.md).

# Exclusion and Not Equals - Valid Expressions

<table data-full-width="true"><thead><tr><th>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>372146004 | Acute chest syndrome| 413839001 | Chronic lung disease|</td><td>27819004 | Pulmonary ossification| : { 116676008 | Associated morphology| = 18115005 | Pathologic calcification| , 363698007 | Finding site| = 31094006 | Structure of lobe of lung| }</td></tr><tr><td>&#x3C;&#x3C; 19829001 | Disorder of lung| MINUS ^ 700043003 | Example problem list concepts reference set|</td><td>233613009 | Fungal pneumonia|</td><td>27819004 | Pulmonary ossification| : { 116676008 | Associated morphology| = 18115005 | Pathologic calcification| , 363698007 | Finding site| = 31094006 | Structure of lobe of lung| }</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>15902003 | Gastric ulcer with hemorrhage|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 55075001 | Bleeding ulcer| , 363698007 | Finding site| = 14374004 | Structure of lymphatic vessel of esophagus| }</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : 116676008 | Associated morphology| != &#x3C;&#x3C; 26036001 | Obstruction|</td><td>233613009 | Fungal pneumonia| 46708007 | Acute gastric ulcer with hemorrhage AND 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|</td><td>233613009 | Fungal pneumonia| 15902003 | Gastric ulcer with hemorrhage|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 55075001 | Bleeding ulcer| , 363698007 | Finding site| = 14374004 | Structure of lymphatic vessel of oesophagus| }</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : [0..0] 116676008 | Associated morphology| != &#x3C;&#x3C; 26036001 | Obstruction|</td><td>244815007 | Pyloric obstruction| 84906002 | Local cyanosis|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 314600001 | Choledochoenterostomy stoma| }</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>244815007 | Pyloric obstruction|</td><td>64572001 | Disease| : { 116676008 | Associated morphology| = 26036001 | Obstruction| , 363698007 | Finding site| = 314600001 | Choledochoenterostomy stoma| }</td></tr></tbody></table>

{% hint style="info" %}
Where necessary, these examples make some assumptions about the membership of the example reference sets.
{% endhint %}

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