Condition (1) ⇒ A * B = A is the mother of B So E * F = E is the mother of F. E is mother. Condition (2) ⇒ A% B = A is the daughter of B. So D% E. = D is the daughter of E. So D is the sister of F. Condition (3) ⇒ A + B = A is the sister of B. So C + D = C is the sister of D. So C is the sister of F