description: Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element. package_name: hl7.fhir.uv.extensions derivation: constraint name: Variable type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/variable'} index: 1 value: choices: [valueExpression] index: 3 valueExpression: {type: Expression, choiceOf: value, index: 4} package_version: 5.3.0-ballot extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/variable base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.3.0-ballot required: [valueExpression, value]