Hi ICU2, just to let you know, you don't need to edit your first post to communicate something new. Just click on the reply button and add more. We love hearing from you! :)
you have used (==) instead of (=) for assining value to trifecta.
So it will check if sum of a,s,b is equal to the value stored in trifecta.If it not equal so it will store 0 because 0 represent as false condition.
Thats why it giving answer diffrnt than you expcted.