Syndrome composition - interpreting an xquery signature in an editor

It was on
my task list to provide an example where interpreting an XQuery with time &
frequency elements would be very difficult (for an editor, for example).

 

Symptoms
below.

We will be
searching for 3 or more occurrences within 30 second interval of
application/responsetime/threshold/breach where Subject is identical.

<?xml version="1.0" encoding="UTF-8"?>

<SymptomStore>

  <Symptom>

    <SymptomId>com/ca/symptom/1</SymptomId>

    <SymptomType>application/responsetime/threshold/breach</SymptomType>

    <CreationDate>2011-05-23T10:00:00</CreationDate>

    <Confidence>ModerateConfidence</Confidence>

    <Reporter>com/ca/application/apm</Reporter>

    <Subject></Subject>

    <Content></Content>

  </Symptom>

  <Symptom>

        <SymptomId>com/ca/symptom/2</SymptomId>

        <SymptomType>system/process/memory/threshold/breach</SymptomType>

        <CreationDate>2011-05-23T10:01:00</CreationDate>

        <Confidence>ModerateConfidence</Confidence>

        <Reporter>com/ca/system/nsm</Reporter>

        <Subject></Subject>

        <Content></Content>

  </Symptom>

  <Symptom>

        <SymptomId>com/ca/symptom/3</SymptomId>

        <SymptomType>system/process/memory/threshold/breach</SymptomType>

        <CreationDate>2011-05-23T10:02:00</CreationDate>

        <Confidence>ModerateConfidence</Confidence>

        <Reporter>com/ca/system/nsm</Reporter>

        <Subject></Subject>

        <Content></Content>

  </Symptom>

    <Symptom>

        <SymptomId>com/ca/symptom/4</SymptomId>

        <SymptomType>application/responsetime/threshold/breach</SymptomType>

        <CreationDate>2011-05-23T10:00:15</CreationDate>

        <Confidence>ModerateConfidence</Confidence>

        <Reporter>com/ca/application/apm</Reporter>

        <Subject></Subject>

        <Content></Content>

    </Symptom>

    <Symptom>

        <SymptomId>com/ca/symptom/5</SymptomId>

        <SymptomType>application/responsetime/threshold/breach</SymptomType>

        <CreationDate>2011-05-23T10:00:20</CreationDate>

        <Confidence>ModerateConfidence</Confidence>

        <Reporter>com/ca/application/apm</Reporter>

        <Subject></Subject>

        <Content></Content>

    </Symptom>

</SymptomStore>

 

Here is one
possible xquery.  Note: Some liberties were taken to keep simple.

let $s := doc('file:///c:/docs/_symptoms/symptomstore.xml')/SymptomStore/Symptom[SymptomType='application/responsetime/threshold/breach' and
Subject='']

let $freq := count($s)

return

  if ($freq >= 3) then (

    if ((fn:seconds-from-dateTime($s[$freq]/CreationDate)
- fn:seconds-from-dateTime($s[1]/CreationDate))
<= 30) then (

      $s

    )

    else

    ()

  )

  else 

  ()

 

How is it possible to
consistently extract the time interval (30) and the frequency (3) from such an
xquery, for the purposes of rendering in an editor?