Condition (1) A%B = A is the mother of B. So P@Q =P is the mother of Q. Condition (2) A&B = A is sister of B. So Q#R = Q is sister of R, so P is the mother of Q and R Condition (3) A$B = A is the daughter of B, So R!S = R is the daughter of S, so S is the father of R, so S is husband of P.