[Ur] Ur reference manual and XML

[Adam Chlipala]

Vasili I. Galchin wrote:
>       I have been reading the demo source code. I read the Section 8.5 
> on XML in the ref manual. If I understand the narrative, it seems 
> there is no formal semantics for XML values. Rather I should read the 
> .ur source that implements the operational semantics of XML. Is this true?

By "formal semantics," do you mean the translation of combinator trees 
into strings of XML source?  You're right that there is no formal 
specification of this in the manual.  I hadn't thought it was 
non-obvious enough to warrant one.

There probably is no Ur "implementation of XML semantics."  Rather, 
that's probably found in various compiler phases in Ur/Web's SML source, 
mostly Monoize.