3 . schemas for semistructured data differ, however, from those for relational or object-oriented data . therefore, typing system and schema formalisms for xml-based semistructured data are extensively studied, and the algorithms both for computing type classification with maximal fixpoints semantics and maximal simulation are proposed, respectively 三、對(duì)半結(jié)構(gòu)數(shù)據(jù)的類型及模式的描述形式進(jìn)行了研究,并分別給出了使用最大不動(dòng)點(diǎn)語(yǔ)義計(jì)算半結(jié)構(gòu)數(shù)據(jù)類型劃分的算法思想和最大仿真(simulation)計(jì)算方法的思想。