Re: [xml-dev] Re: Schemas: Different Strokes From Different Folks
On Wed, Jan 18, 2017 at 4:17 PM, Henry S. Thompson <[email protected]> wrote:
I understood Murata to have proved for RELAX NG that given two XML
languages, each (weakly) generated by a RELAX NG schema, the union _of
the languages_ would be generated by the union of the schemata.
Indeed, the proof is trivial. Let a be the root pattern of schema A, and b be the root pattern of schema B. Then <choice><ref name="a"/><ref name="b"/></choice> matches any document that matches either a or b or both. And since there are no constraints on the subpatterns of a choice pattern other than those inherited from the context of the choice pattern (which here is null), all such patterns are valid.
GMail doesn't have rotating .sigs, but you can see mine at http://www.ccil.org/~cowan/signatures