Marcus Harnisch writes:
 1. delete string following point (thus modifying the end-open
extent)
 
 2. insert string preceeding point (placing it outside the extent)
 
 3. insert string deleted in 1. before string inserted in 2. (placing
    it outside the extent)
 
 4. delete string preceeding point 
Should be:
1. delete string following point (thus modifying the end-open extent)
2. insert string preceeding point (placing it outside the extent)
3. delete string preceeding point
4. insert string deleted in 1. before string inserted in 2. (placing
   it outside the extent)
-- Marcus