Notation
A set intersection of two sets, A and B, denoted by A ∩ B, is a subset of A or B that contains all elements that are in both A and B. In other words, A ∩ B := { x : x in A and x in B}.
A set union of two sets, A and B, denoted by A ∪ B, is a set that contains precisely the elements that are in A or in B. In other words, A ∪ B := { x : x in A or x in B}.
A set difference of two sets, A and B, denoted by A – B or A\B, is a subset of A that contains all elements in A that are not in B. In other words, A – B := { x : x in A and x not in B}.
The summation symbol, ∑, represents the sum of all members over the set, for example...
