Abstract

XCL 1.0 is an XML markup language designed as a concrete (serialization) syntax for Common Logic [CL]. The XCL 1.0 markup language is formally defined by ISO/IEC 24707:2007 Information technology -- Common Logic (CL): a framework for a family of logic-based languages [ISO24707], designed to enable interchange and interoperation of CL expressions across the World Wide Web.

Status

This web page comprises a distribution point for the final copies of the XML Common Logic (XCL) 1.0 DTD as submitted to ISO during the standardization process.

Please note that none of the documents described herein have any formal status, and their publication should not be construed as being a work of, nor endorsed by, any corporate, academic, standards, or other organization. They are provided for the convenience of the Web community and come with NO WARRANTY. Neither the author nor the copyright holders make any representation about the suitability of the XCL 1.0 DTD for any purpose.

Likewise, references to "ISO 24707" in this document are not meant to imply any formal association between this site or its documents and ISO/IEC, nor any statement regarding the status of ISO 24707 as an International Standard.

The author has endeavoured to provide accurate copies of the XML file comprising the XCL 1.0 DTD as specified in Appendix C of ISO/IEC 24707. This includes both commented, uncommented, and XML Namespace prefixed versions of the XCL DTD. Any discrepancies between these files and the published standard should be brought to the attention of the author. If any discrepancies are found it should be noted that in all cases the ISO/IEC document is to be considered authoritive.

This document may be updated, replaced, rendered obsolete by other documents, or removed from circulation at any time. While copyrighted, distribution of this document is unlimited.

XCL File Distribution

This distribution of the XCL 1.0 DTD includes the following files:

xcl1.dtd

This is an amended XCL 1.0 DTD based on the DTD that appears in the body of the ISO/IEC 24707 standard, with corrected section numbers, dates, and a corrected architecture support declaration. While not identical with the standard, this is the recommended XCL 1.0 DTD, and the file located at the canonical system identifier (though resolution is currently disabled).

  http://purl.org/xcl/1.0/xcl1.dtd

xcl1c.dtd

The XCL 1.0 DTD named "xcl1c.dtd" is the DTD submitted to the ISO committee and incorporated into the standard. This included minor textual changes such as an alteration in the section numbers used in the DTD comments. This file is the closest in content to the DTD provided in Appendix C of ISO/IEC 24707 as it contains all the comments and notes and errors included in the standard. This includes one minor mistake: an error in the processing instruction used for the architectural support declaration. This should have no effect on normal DTD processing.

xcl1-v1.18.dtd

The file "xcl1-v1.18.dtd" is the same as the xcl1c.dtd minus the comments.

xcl1p.dtd

The file "xcl1n.dtd" is again functionally the same as the "xcl1c.dtd" but uses an "xcl:" XML Namespace prefix.

catalog

The TR 9401 Catalog Data File for XCL 1.0.

xml1.dcl

The SGML Declaration for XML 1.0

xml1n.dcl

The SGML Declaration for XML 1.0, amended for compatibility with XML validation. This is for use with James Clark's SP toolkit (which actually pays attention to such things).

test1.xcl

An XCL 1.0 example (test) file. Nonsensical but syntactically valid.

xcl1.zip

A ZIP file distribution (21K) of all above files.

XCL 1.0 DTD documentation

This is HTML documentation autogenerated by dtd2html, part of Earl Hood's perlSGML toolkit.
[If you have linux installed you can easily install perlSGML from your package manager — it runs on the command line.]

Future Work

The differences between the XCL DTD published in ISO/IEC 24707:2007 and the recommended XCL 1.0 DTD shown above are minor and non-functional, as they only appear in XML comments. These include an error in the reference to the standard (we'd thought it would appear in 2006, not 2007), and a few mistakes in the recommended architecture support declaration, used in architectural forms processing.

One change that was suggested to the editor that didn't make it into the standard (and hence is not included in any of the DTDs) is the recommended addition of an xml:lang attribute to the <comment> element type, permitting a declaration of the natural language of a comment (and opportunity to include comments in multiple languages).

The amended XCL DTD will be submitted to the ISO editors with comments. It is known that there are errors in the XCL DTD as published in the current standard that need to be fixed, and the ISO committee is maintaining a defect report.

XML Common Logic (XCL) 1.0

XCL File Distribution

Abstract

Status

XCL File Distribution

Contents

Future Work

Appendix A. References