meta-data与model

摘自：mof1.4 spec:
There are three cases where it is convenient to use the “meta-” prefix as part of MOF terminology:
1. The term “metadata” is used to refer to data whose purpose is to describe other data.
2. The term “metamodel” is used to refer to a model of some kind of metadata.
3. The term “metaobject” is used to refer to an abstract or technology specific object that represents metadata.

In each case, the term is used across all meta-levels and has a deliberately imprecise meaning.

4. The metamodel layer is comprised of the descriptions (i.e., meta-metadata) that define the structure and semantics of metadata.
Meta-metadata is informally aggregated as metamodels.
A metamodel is an “abstract language” for describing different kinds of data; that is, a language without a concrete syntax or notation.

1)=>Describe(metadata, data)
2)=> metamodel=ModelOf(metadata)-----A)
3)=> Represent(metaobject, metadata)
4)=> metamodel=Set(descriptions about 结构和语义(metadata) not 具体的语法或标记(metadata)) ^ meta-metadata<=metamodel----------B)

由A) and B)=>meta-metadata<=ModelOf(metadata)=>ModelOf="meta-"+"余量"
=>metamodel=("meta-"+"余量")metadata
=>metamodel=meta-metadata+("余量")(metadata)
两边去掉meta=>
model=metadata+("余量")(data)

这个余量是什么，可能是数据结构化（行为）for行为语义