A set is a collection of elements enclosed in curly braces. A set is a subset of another set if all elements of A are in B. Every set contains an empty set (null set)
A proper subset contains some but not all elements of another set. Proper subset is denoted by '⊂' symbol. A proper subset has fewer elements than the original set
A subset is a part of another set, written as A ⊆ B. Every set is a subset of itself and the empty set is a subset of all sets. The number of subsets of a set with n elements is 2n
An element is any distinct object belonging to a set. Set membership is denoted by "∈" symbol. The symbol "∉" represents the negation of membership. The symbol "∈" was first used by Giuseppe Peano in 1889
A set A is a subset of B if all elements of A are in B. Inclusion (or containment) is the relationship between sets. A k-subset contains k elements. The empty set is a vacuously subset of any set
A set is a collection of elements enclosed in curly braces. A subset contains all elements of another set. The empty set is an improper subset of itself but a proper subset of others