When i put this rule in the expression,
if(equals(item()?['Ruleset_1'],'1'),concat('This text is added when ruleset_1 equals to 1 : ',add(add(int(item()?['Storenumber']),int(item()?['Year'])),int(item()?['Period']))),'')
Then it counts the coloms L+M+R
The intention is that it displays what is in Colom (Storenumber-Year-period) Colom L - M and R