I'm writing today to ask for a heading/starting point in how I might approach this problem proposed to me involving Set Theory.
From my understanding, this proof is asking us to show that the set containing all the elements in A minus the set of all elements common to the sets B1,B2,...,Bn is equal to the set containing all the elements of A not in a particular set on Bn. I can see this making sense, as it's saying there's a set of values in B1, B2, Bn that are not in at least one of the iterations of the Union of (A-Bi), however I am very stuck on how to begin formally proving this using Set Theory. Can someone give me a direction/heading for this? I'm familiar with calculus and more number theory proofs but I'm completely lost on how to begin such a proof like this.