Expression Constraint Language

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If no expression constraint operator or membership function is applied, the expression constraint is satisfied only by the specified concept. For example, the expression constraint below is satisfied only by the concept

Scg expression
404684003 |Clinical finding|
.
Scg expression
Borderridge
ShowFormatblock
   404684003 |Clinical finding|
Please note that this expression constraint is equivalent to an expression that looks the same but is written in SNOMED CT Compositional Grammar.

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A single 'less than' sign (i.e. "<") indicates that the expression constraint is satisfied by all descendants of the specified concept. The expression constraint below evaluates to the set of all subtypes (both direct children and transitive subtypes) of

Scg expression
404684003 |Clinical finding|
, using the brief syntax.
Scg expression
Borderridge
ShowFormatblock
   < 404684003 |Clinical finding|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   descendantOf 404684003 |Clinical finding|
The descendantOf function is primarily used on concepts, which serve as the 'grouper' of a set of values (e.g.
Scg expression
404684003 |Clinical finding (finding)|
,
Scg expression
272141005|Severities (qualifier value)|
,
Scg expression
258666001|Unit (qualifier value)|
).

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Two consecutive 'less than' signs (i.e. "<<") indicates that the expression constraint is satisfied by all descendants of the specified concept plus the specified concept itself. The expression constraint below evaluates to the set of descendants of

Scg expression
73211009 |Diabetes mellitus|
, plus the concept
Scg expression
73211009 |Diabetes mellitus|
 itself.
Scg expression
Borderridge
ShowFormatblock
   << 73211009 |Diabetes mellitus|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   descendantOrSelfOf 73211009 |Diabetes mellitus|
The descendantOrSelfOf function is primarily used for attribute values, which refer to a specific clinical value (e.g.
Scg expression
73211009 |Diabetes mellitus|
,
Scg expression
73761001 |Colonoscopy|
,
Scg expression
385055001 |Tablet dose form|
), but any specialization of this value is also acceptable.

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A 'less than' sign directly followed by an exclamation mark (i.e. "<!") indicates that the expression constraint is satisfied by the set of immediate children of the specified concept. The children of a concept are those concepts that are the source of a non-redundant

Scg expression
ShowPartsterm
116680003|is a|
 relationship whose target is the given concept. The expression constraint below, represented using the brief syntax, evaluates to the set of immediate children of the concept
Scg expression
404684003|Clinical finding|
.
Scg expression
Borderridge
ShowFormatblock
   <! 404684003|Clinical finding|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   childOf 404684003|Clinical finding|

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A single 'greater than' sign (i.e. ">") indicates that the expression constraint is satisfied by all ancestors of the specified concept. The expression constraint below, using the brief syntax, evaluates to the set of all supertypes (both direct parents and transitive supertypes) of

Scg expression
40541001 |Acute pulmonary edema|
:
Scg expression
Borderridge
ShowFormatblock
   > 40541001 |Acute pulmonary edema|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   ancestorOf 40541001 |Acute pulmonary edema|

...

Two consecutive 'greater than' signs (i.e. ">>") indicates that the expression constraint is satisfied by all ancestors of the specified concept plus the specified concept itself. The expression constraint below evaluates to the set of ancestors of

Scg expression
40541001 |Acute pulmonary edema|
, plus the concept
Scg expression
40541001 |Acute pulmonary edema|
.
Scg expression
Borderridge
ShowFormatblock
   >> 40541001|Acute pulmonary edema|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   ancestorOrSelfOf 40541001 |Acute pulmonary edema|

...

A 'greater than' sign directly followed by an exclamation mark (i.e. ">!") indicates that the expression constraint is satisfied by the set of immediate parents of the specified concept. The parents of a concept are those concepts that are the target of a non-redundant |is a| relationship whose source is the given concept. The expression constraint below, represented using the brief syntax, evaluates to the set of immediate parents of the concept

Scg expression
40541001 |Acute pulmonary edema|
.
Scg expression
Borderridge
ShowFormatblock
   >! 40541001 |Acute pulmonary edema|
Using the long syntax, the above expression constraint may be represented as:
Scg expression
Borderridge
ShowFormatblock
   parentOf 40541001 |Acute pulmonary edema|

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The memberOf function is represented in the brief syntax using a 'caret' character (i.e. "^") and must be immediately followed by a single concept id for a concept-based reference set. For example, the following expression constraint is satisfied by the set of concepts which are members of

Scg expression
ShowPartsterm
700043003|Example problem list concepts reference set|
:
Scg expression
Borderridge
ShowFormatblock
   ^ 700043003 |Example problem list concepts reference set |
Using the long syntax the expression constraint is represented as:
Scg expression
Borderridge
ShowFormatblock
   memberOf 700043003 |Example problem list concepts reference set |
Please note that to represent the members of a reference set, which is itself composed of members of two or more other reference sets, an intensional definition should be created. For example, to refer to the members of the
Scg expression
AAAAAA |Allergen reference set|
, which is defined as containing the members of the
Scg expression
DDDDDD |Drug allergen reference set|
 and the members of the
Scg expression
FFFFFF |Food allergen reference set|
, then a row should be inserted into a query reference set with:
Scg expression
Borderridge
ShowFormatblock
   referencedComponentId = AAAAAA
and
Scg expression
Borderridge
ShowFormatblock
   query = ^ DDDDDD |Drug allergen reference set| OR ^ FFFFFF |Food allergen reference set|
(where AAAAAA, DDDDDD and FFFFFF are the concept identifiers of the respective reference sets).

...

A single 'star' (i.e. "*") may be used in the place of a concept reference to represent any concept in the substrate. The expression constraint below evaluates to the set of all concepts in the given substrate.

Scg expression
Borderridge
ShowFormatblock
   *
Using the long syntax, the above expression constraint may also be represented as:
Scg expression
Borderridge
ShowFormatblock
   ANY
This wildcard character (or 'ANY' keyword) may be used anywhere within an expression constraint that a concept reference may be used. In many situations, the wildcard is equivalent to the following expression constraint:
Scg expression
Borderridge
ShowFormatblock
   << 138875005 |SNOMED CT concept|
However, some situations exist in which the concept
Scg expression
138875005 |SNOMED CT concept|
 is not included in the substrate, and therefore cannot be used to determine the full set of concepts available. In other cases, the single character wildcard may serve as a convenient shortcut for the longer expression constraint above.

Please note that the following three expression constraints evaluate to the same set of concepts:

Scg expression
Borderridge
ShowFormatblock
   *
Scg expression
Borderridge
ShowFormatblock
   << *
Scg expression
Borderridge
ShowFormatblock
   >> *
The expression constraint below evaluates to all concepts in the substrate minus the root concept:
Scg expression
Borderridge
ShowFormatblock
   < *
And the expression constraint below evaluates to all non-leaf concepts in the substrate:
Scg expression
Borderridge
ShowFormatblock
   > *
Finally, the expression constraint below evaluates to all concepts that are referenced by any reference set in the substrate:
Scg expression
Borderridge
ShowFormatblock
   ^ *