The attempt to make redundant derivations using repeated Exclusive facets with 
the same value works only part way. According to the definitions, One can 
derive a from decimal setting using maxExclusive = 29, redundantly derive b 
from a using maxExclusive = 29, but are then not permitted to derive c from b 
again using maxExclusive = 29. (Weird, but that's the way it is.) 

This one-level redundancy is explicitly permitted by the definitions of 
minExclusive and maxExclusive, but didn't make its way into the descriptions of 
the schema components, nor of the XML representation summaries. So they 
contradict the definition. I suspect this is an editorial error in 2E PER. 

See
http://lists.w3.org/Archives/Public/www-xml-schema-comments/2004JanMar/0085.html