Maths, Mathematics, Discrete Mathematics, Sets.
the set that has no elements. Clearly ∅ is a subset of every set. The singleton It is a set that contains just one element x. We denote it by A = {x}. Subset A set S is a subset of a set T (denoted S ⊆ T) if whenever s ∈ S then s ∈ T, and in this case, the set T is said to be a superset of S