We use ' (the apostrophe) to denote the complement of a set. A' is all the items which are not in set A. A B means that set A is a subset of set B. This means that every member of set A also appears in set B. ... For example, if A is the set of numbers which are both odd and even then A = .
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Answer:
We use ' (the apostrophe) to denote the complement of a set. A' is all the items which are not in set A. A B means that set A is a subset of set B. This means that every member of set A also appears in set B. ... For example, if A is the set of numbers which are both odd and even then A = .
Answer: It means Null set .A set with no element
is an empty set or null set