description of the relationship between URIs and literals and, in order to evolve, it requires the explicit contribution of external machines to read and write to it.

However, the amount of procedural information that is actually encoded in the Semantic Web can vary. At one extreme, the Semantic Web is a read-only substrate that has limited effect on how a computation evolves. At the other extreme, the Semantic Web is the representational substrate for not only the data aspects of a computation, but also the algorithmic and machine representations as well.

This article has presented an analysis of the various

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## Acknowledgments

Marko A. Rodriguez and Johan Bollen are funded by a grant from the Andrew W. Mellon Foundation.

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