Tree construction for XML to XML document transformation

A system, the system comprising a processor and a memory coupled to the processor, for transforming a user-supplied DTD satisfying a first XML grammar into a PDTD satisfying a second XML grammar, the system comprising:

• means for converting DTD declarations of alternate content to sequences;
• means for converting DTD declarations of optional content to mandatory content;
• means for converting DTD declarations of imbedded sequences to subsequences;
• means for demoting attribute definitions of DTD elements having attributes to children of the DTD elements having attributes;
• means for converting recursions into repetitions;
• means for demoting imbedded compound repetitions from element declarations having imbedded compound repetitions;
• and
• means for demoting imbedded leaves from elements having imbedded leaves.

A computer program product for transforming a user-supplied DTD satisfying a first XML grammar into a PDTD satisfying a second XML grammar, the computer program product comprising:

• a recording medium;
• means, recorded on the recording medium, for converting DTD declarations of alternate content to sequences;
• means, recorded on the recording medium, for converting DTD declarations of optional content to mandatory content;
• means, recorded on the recording medium, for converting DTD declarations of imbedded sequences to subsequences;
• means, recorded on the recording medium, for demoting attribute definitions of DTD elements having attributes to children of the DTD elements having attributes;
• means, recorded on the recording medium, for converting recursions into repetitions;
• means, recorded on the recording medium, for demoting imbedded compound repetitions from element declarations having imbedded compound repetitions;
• and
• means, recorded on the recording medium, for demoting imbedded leaves from elements having imbedded leaves.