A computable rule that is used to define a set of clinical meanings.

Notes

• SNOMED CT expression constraints are defined using the 

  Gloss
  t expression constraint language (ECL) GlosTerm Expression Constraint Language

  .
• Expression constraints can be used as:for a variety of purposes including:
  • Specifying 

    Gloss
    t value set bindings

     that constrain the values that can be entered in a particular 
  • formal constraints on the content of a particular data element in an

    Gloss
    t electronic health recorddata entry context

    .
  • Representing an 

    Gloss
    t intensional

     definitions of concept-based reference sets.

    subset definition

    , which may be used to determine the membership of a 

    Gloss
    t reference set

  • Querying 

    Gloss
    t electronic health records

     for record entries that contain specified sets of 

    Gloss
    t concepts

     and/or machine processable queries that identify a set of matching

    Gloss
    t precoordinated expressions

     or
  • Defining the

    Gloss
    t postcoordinated expressions

    .

    SNOMED CT concept model

     by specifying the sets of concepts in a 

    Concept
    t concept model domains

     and the constraints that restrict the

    Gloss
    t range GlosTerm concept model range

     of an values applicable to each 

    Gloss
    t attribute

     defined in the .

Related Links

• Glossary

  • Gloss
    t SNOMED CT concept model

    .

...

• • expression

  • Gloss
    t Expression constraint language

• Specification
  • Expression Constraint Language - Specification and Guide