Gulp

Joe Armstrong (AL/EAB) <>
Wed Mar 2 13:36:28 CET 2005


  OMG anyone?

  Some quotes from the amazing Meta-Object Facility Specification available at

  http://www.omg.org/docs/formal/02-04-03.pdf

The Meta Object Facility Specification is what is used to
descibe the meta-meta model of a UML model (was that right?)- this 358 pages mastodon 
document is full of little gems like (section 2.2.1, page 34):

    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.

I'm having slight problems understanding this:

    Let's try an put the clause "describing the meta-meta model of a UML-model"
into my language understanding engine.

     
    "describing the meta-meta model of a UML-model" 

    => "describing X" where X = "the meta-meta model of a UML-model"

    I think that

	"the meta-meta model of a UML-model" => "meta-meta-meta model"

    and "describing X" => a meta-model of X

    so this should be a meta-meta-meta-meta model

    But is this 

	 "a language without a concrete syntax or notation" 

    This is the puzzling bit.


/Joe



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