AQL problem with "diff"

[Dave Matthews]

This query returns zero results:

acedb at nightshade> aql @AvailableToMap := \
(select S from S in class Sequence) \
diff \
(select S from S in class Sequence \
where exists_tag S->Contig->Contig_members->Probe)
// Response: 21 bytes.
// 0 Active Objects

But separately the first select gives 151,260 hits and the second one only
22,325.

If I swap the order of the selects I get 22,325 hits.

This is with sgifaceserver 4_9i on Solaris 8.
Host nightshade.plbr.cornell.edu, port 44000.

- Dave

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