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RE: [xsl] The operator '!=' returns false when one operand doesn't exist

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> We have an issue with the XPath '!=' operator that has
> a strange behavior when one of its operand doesn't
> exist in the instance document. It returns 'false"
> when you would expect "true" or some kind of exception
> to be raised.

A op B means "if some $a in A, $b in B satisfies $a op $b"

So if A or B is empty, the result will always be false, regardless which
operator you are using.

You nearly always want to write not(a=b) rather than a!=b.

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx 


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