[isabelle-dev] Wrong ring hierarchy in Isabelle 2007

[Steven Obua]

Hi,

I just discovered that another last minute "FIXME" has changed the 
hierarchy of rings in Isabelle2007 such that "real" is not of sort 
"lordered_ring" any more. More generally, "ordered_ring" is not an 
"lordered_ring" any more. This is pretty unfortunate as it renders the 
whole HOL-Complex-Matrix package in Isabelle 2007 garbage. Maybe in the 
future one should refrain from last minute fixes which one does not 
fully understand.

Steven