[xsl] Adjacent grouping?

["rus tle profrustyleafiii@xxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hello All,

I am trying to remove attribute values in a list based on a frequency
parameter.

Is this possible in XSLT 2? I cannot see how to tackle the problem without
being able to store the last attribute value added to the result tree so that
I can compare against it for the following attribute values? I am told that
there is no way to query the result tree and so I am at a loss as to whether
XSLT can actually do what I require?

To illustrate, please see the example below.

The frequency parameter is 30. I would like to remove all values that are
"within 30" of the last value used. If the first value is 0 then I would like
to remove all the following attribute values that are less than 30 plus the
last value added to the result tree (in this case 0). The only way I can think
to do this is by somehow caching the last value that was copied to the result
tree so I can compare against it with the next value.

It was suggested to me that adjacent grouping my work? I am a recent beginner
to XSLT and would love to learn more about how it might help me achieve the
result I am looking for?

Thanks,

Rusty

Before:

<p frequency=b30">
    <Content value="0"/>
    <Content value=b10b/>
    <Content value=b15b/>
    <Content value=b18b/>
    <Content value=b22b/>
    <Content value=b26b/>
    <Content value=b34b/>
    <Content value=b37b/>
    <Content value=b56b/>
    <Content value=b99b/>
    <Content value=b101b/>
    <Content value="115"/>
    <Content value="118"/>
    <Content value="129"/>
</p>
After:

<p frequency="30">
    <Content value="00"/>
    <Content value=""/>
    <Content value=""/>
    <Content value=""/>
    <Content value=""/>
    <Content value=""/>
    <Content value="34"/>
    <Content value=""/>
    <Content value=""/>
    <Content value="99"/>
    <Content value=""/>
    <Content value=""/>
    <Content value=""/>
    <Content value="129"/>
</p>