how about changing the first line of your DSL map to...
[condition][]{varname} is a Volume where {constraints} = {varname} : RawVolumeTs (where
{constraints} )
That way, your DSL would read...
rule "RT(2) against FT(32)"
when
V1 is a Volume where status is "NA" and sourceId is "ABC"
V2 is a Volume where status is "NA" and sourceId is "XYZ"
then
end
and the resulting DRL would read...
rule "RT(2) against FT(32)"
when
V1 : RawVolumeTs (status == "NA", sourceId == "ABC")
V2 : RawVolumeTs (status == "NA", sourceId == "XYZ")
then
End