Chapter 2.5 - Non-standard XPath syntax

The final piece of example code in Chapter 2.5 contains non-standard (I 
assume incorrect) XPath 1.0 syntax:

relevant="pay:payment/@as == 'credit'"

The normal syntax in XPath 1.0 where an attribute is required to have a 
particular value would be
relevant="pay:payment/@as = 'credit'"

Andrew Watt