URN Topology
CTS URNs can be thought of as a kind of hierarchical coordinate system
identifying shorter or longer stretches within the linear
sequence of a text.
Version 3 of Canonical Text Services defines a
UrnTopology request
that compares a pair of CTS URNs
within the same work.
The order of comparison is significant.
There are seven mutually exclusive possible relations, summarized here
for two URNs, urn1 and urn2.
- EQUALS: the two CTS URNs refer to exactly the same span.
- PRECEDES: the entire content of urn1 precedes urn2
- FOLLOWS: the entire content of urn1 follows urn2 (i.e., converse of PRECEDES, and the entire content of urn2 precedes urn1)
- CONTAINS: urn1 contains the entire content urn2
- IS_CONTAINED_BY: the entire content of urn1 falls within urn2 (i.e., the converse of CONTAINS, and urn2 contains the entire content of urn1)
- PRECEDES_AND_OVERLAPS: some of the content of urn1 precedes urn2, some overlaps, but urn1 does not completely contain urn2.
- OVERLAPS_AND_FOLLOWS: some of the content of urn1 overlaps urn2, some follows, but urn1 does not completely contain urn2 (i.e., the converse of PRECEDES_AND_OVERLAPS, and some of the content of urn2 precedes urn1, some overlaps, but urn2 does not completely contain urn1.)
Page last modified: Aug. 11, 2008
Digital Incunabula: always work in progress packaged on Dec. 20, 2008; installed on this site Sat, 20 Dec 2008. Edited by and copyright 2004-2008 Neel Smith except where otherwise noted.
This work is licensed under a Creative Commons License.
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