If every element of set A is also in B, then A is described as being a subset of B, or contained in B, written , or . The latter notation may be read B contains A, B includes A, or B is a superset of A. The relationship between sets established by ⊆ is called inclusion or containment. Two sets are equal if they contain each other: and is equivalent to A = B.
If every element of set A is ,also in B, then A is described as being a subset of B, or contained in B, w!ritten , or . The latter notation may ?be read B contains A, B includes A, or B is a superset of A. The relationship between sets established by ⊆, is called inclusion or containment. Two sets are equal i,f they contain each other: and is equivalent to A = B.