Source:http://linkedlifedata.com/resource/umls/id/C1550535
HL7V3.0: <p>Associates a derived Act with its input parameters. E.G., an anion-gap observation can be associated as being derived from given sodium-, (potassium-,), chloride-, and bicarbonate-observations. The narrative content (Act.text) of a source act is wholly machine-derived from the collection of target acts.</p>