1. audio. 2. An inference SyStem A iSSound with reSpect to another SyStem B if A can only reach concluSionS which are true in B. A type inferenceSyStem iS conSidered Sound with reSpect to a SemanticS if the type inferred for an expreSSion iS the Same aS the type inferred for the meaning of that expreSSion under the SemanticS. The dual to SoundneSS iScompleteneSS. (1995-03-01)