no match because hd($query[0],$hash_mismatch->{'S1'}[0]) > $d even though hd($query[1],$hash_mismatch->{'S2'}[1]) < $d i.e in this case only 1 element of query satisfy, which doesn't count. To be valid, both of query elem must satisfy "hd<=$d".

I concur with BrowserUk that you need to straighten out your specs before you can get any sensible feedback on this question. The quoted passage makes no sense at all. The elements of @query are identical; i.e. one of them satisfies hd<=$d if and only if the other one does.