Saxon

The index is being constructed correctly (a hash map from BooleanValue to List<NodeInfo>) but the lookup fails because no attempt is made to convert the untypedAtomic value to a boolean. There's plenty of logic dealing with the case where the USE value is untypedAtomic, but none for the case where the SOUGHT value is untypedAtomic. (Of course, if the USE value is a string, it all works cleanly.)

In a simple case like this where the USE values all have the same type and it's known statically, then this really shouldn't be a problem. It only gets difficult where there are multiple types.

While building the index we take care to maintain the property keyTypesPresent, but the value seems to be unused when it comes to using the index. (There's no change here from 9.9 or 9.8 so it looks like a long-standing problem.)

Iterating over the types listed in keyTypesPresent, and for each one, converting the sought value to the relevant type before doing a lookup in the index, appears to solve the problem. But we need to fast-path cases where this isn't necessary.

Added qt3 test cases in prod-Predicate, predicates-33 to -35. Test -35 involves comparison with multiple types and elimination of duplicates.

Leaving bug as resolved until fix applied to the Saxon 10 maintenance release.