Set Analysis - Exclude some values but keep nulls

[im]

Hi

I've been searching everywhere but all solutions for exclude in set analysis also take out null values, which I don't want.

=Count(distinct {$< OverallOutcome-={'Set Up in Error'}>} ReferenceNumber)  excludes all nulls

I  tried - 

=Count(distinct  ReferenceNumber) -Count(distinct {$< OverallOutcome={'Set Up in Error'}>} ReferenceNumber) 

but that does row by row calculations in effect assigning negative values to errors and removing them twice.

Help!

[Shubham_Deshmukh]

Try this: 

https://community.qlik.com/t5/QlikView-App-Development/Set-analysis-exclude-but-keep-null/m-p/840513

[sunny_talwar · Accepted solution]

How about this

=Count(DISTINCT {$<ReferenceNumber = e({<OverallOutcome ={'Set Up in Error'}>})>} ReferenceNumber)