Cevap :
Answer: Additive Group Conditions: Identity Element, Additive Inverse and Associativity
Verify
Identity element: A+e=e+A=A (is there an e set?) for the empty set (A-empty set) ∪ (Empty set-A) = A ∪ empty set = A yeah the empty is identity element for this operation
Additive Inverse A+(-A)=(-A+A)=empty set it is easy that every element under this operation is an inverse of itself.
Associativity is easy so it is omitted.