# Nested Expression Constraints - Valid Expressions

<table data-full-width="true"><thead><tr><th width="361.171875">Expression Constraint</th><th width="254.9375">Precoordinated</th><th>Postcoordinated</th></tr></thead><tbody><tr><td>&#x3C;&#x3C; (^ 700043003 | Example problem list concepts reference set| )</td><td>394659003 | Acute coronary syndrome|</td><td>194828000 | Angina| : 255234002 | After| = 22298006 | Myocardial infarction| 194828000 | Angina| 371807002 | Atypical angina|</td></tr><tr><td>^ (&#x3C; 450973005 | GP/FP health issue reference set| )</td><td>140004 | Chronic pharyngitis|</td><td>297009 | Acute myringitis|</td></tr><tr><td>(&#x3C; 404684003 | Clinical finding| : 363698007 | Finding site| = &#x3C;&#x3C; 39057004 | Pulmonary valve structure| ) AND ^ 700043003 | Example problem list concepts reference set|</td><td>204351007 | Fallot’s trilogy|</td><td>457652006 | Calcification of pulmonary valve|</td></tr><tr><td>(&#x3C; 404684003 | Clinical finding| : 363698007 | Finding site| = &#x3C;&#x3C; 39057004 | Pulmonary valve structure| ) AND (&#x3C; 64572001 | Disease| : 116676008 | Associated morphology| = &#x3C;&#x3C; 415582006 | Stenosis| )</td><td>204351007 | Fallot’s trilogy|</td><td>19036004 | Rheumatic heart valve stenosis| : { 363698007 | Finding site| = 39057004 | Pulmonary valve structure| , 116676008 | Associated morphology| = 415582006 | Stenosis| } 56786000 | Pulmonic valve stenosis|</td></tr><tr><td>(&#x3C;&#x3C; 17636008 | Specimen collection| : 424226004 | Using device| = &#x3C;&#x3C; 19923001 | Catheter| ) . 363701004 | Direct substance|</td><td>78014005 | Urine|</td><td>87612001 | Blood|</td></tr><tr><td>(&#x3C;&#x3C; 404684003 | Clinical finding (finding)| OR &#x3C;&#x3C; 272379006 | Event (event)| ) : 255234002 | After| = &#x3C;&#x3C; 71388002 | Procedure (procedure)|</td><td>235948002 | Postoperative acute pancreatitis|</td><td>64572001 | Disease| : { 370135005 | Pathological process| = 441862004 | Infectious process| , 255234002 | After| = 387713003 | Surgical procedure| , 116676008 | Associated morphology| = 112633009 | Surgical wound| } 441795000 | Infected seroma after surgical procedure|</td></tr><tr><td>&#x3C;&#x3C; 125605004 | Fracture of bone| : [0..0] ((&#x3C;&#x3C; 410662002 | Concept model attribute| MINUS 363698007 | Finding site| ) MINUS 116676008 | Associated morphology| ) = *</td><td>125605004 | Fracture of bone|</td><td>64572001 | Disease| : { 363698007 | Finding site| = 71341001 | Bone structure of femur| , 116676008 | Associated morphology| = 20946005 | Fracture, closed| } 439987009 | Open fracture of bone|</td></tr><tr><td>&#x3C; 404684003 | Clinical finding| : 47429007 | Associated with| = (&#x3C; 404684003 | Clinical finding| : 116676008 | Associated morphology| = &#x3C;&#x3C; 55641003 | Infarct| )</td><td>71023004 | Pericarditis secondary to acute myocardial infarction|</td><td>3238004 | Pericarditis (disorder)| : 47429007 | Associated with| = 57054005 | Acute myocardial infarction|</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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