Case statement in a compute expression to backfill null values or to effect binning.

Here is a use case where null values are backfilled with 'unspec' or different texts depending on certain values of a field called timeUntil.Using a compute expression with a text type, enter the statement in the SAQL expression.
case
when 'Date_Time_Priority_Assigned__c'  is null then "Unspec"
when 'Time_Until_Prioritized_Days__c'  >0 and 'Time_Until_Prioritized_Days__c'  <=1  then "Prioritized w/in 24 Hrs."
when 'Time_Until_Prioritized_Days__c' >1 and  'Time_Until_Prioritized_Days__c'  <= 2
then  "Prioritized within 48 Hrs."
when 'Time_Until_Prioritized_Days__c' >2
then  "Prioritized after 48 Hrs."  
else "Unspec" end