description: 'Provides an alternate expression containing the compiled JSON ELM for an expression. (**NOTE**: The expectation is that this extension will transition to the core extensions pack)' package_name: rs/hl7.fhir.us.davinci derivation: constraint name: AlternativeExpression type: Extension elements: extension: {index: 0} url: pattern: {type: uri, value: 'http://hl7.org/fhir/us/davinci-dtr/StructureDefinition/alternativeExpression'} type: uri index: 1 value: short: Alternate expression containing compiled JSON ELM. choices: [valueExpression] index: 3 valueExpression: {type: Expression, short: Alternate expression containing compiled JSON ELM., choiceOf: value, index: 4} package_version: dtr-2.1.0 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/us/davinci-dtr/StructureDefinition/alternativeExpression base: http://hl7.org/fhir/StructureDefinition/Extension version: 2.1.0 required: [value, valueExpression]