我下载了WordNet2.0全套.在RDF/XML文档,wnfull.rdfs,有下面这个元素使用,例如,&wn20schema;AdverbSynset作为属性值(在地方的URI将预期).我知道如何#,url/并且value:常用,但这种&...;符号是什么？
<rdfs:Class rdf:about="&wn20schema;Synset" />
<rdfs:Class rdf:about="&wn20schema;AdjectiveSynset" />
<rdfs:Class rdf:about="&wn20schema;AdjectiveSatelliteSynset" />
<rdfs:Class rdf:about="&wn20schema;AdverbSynset" />