> It does pose an interesting question though, because in my case surely
> 
> Race/RaceType >= 'R' and Race/RaceType <= 'R'
> 
> AND
> 
> Race/RaceType >= 'R' or Race/RaceType <= 'R'
> 
> would do the same? 


no the first is true just if both branches are true, and the second is
true if either branch is true.

> Which is fine in the XSLT world but try 
> explaining that to the logic gurus!


the operators follow standard propositional calculus here, so long as
you remember that 

sequence operator value
means

exists x in sequence such that x operator value.

so in your case

Race/RaceType >= 'R'

means (and could be written in xpath as)

some $r in Race/RaceType satisfies ($r  >= 'R')

David

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