'P ∆ Q' means that P is the mother of Q, 'P  Q' means that P is the father of Q, 'P # Q' means that P is the sister of Q. Which of the following represents 'M is the daughter of R' ?
R  M ∆ N.
R ∆ N  M.
R # M  N.
R  M means R is the father of M, but M could be male or female. Next R∆N means R is mother. Hence M is female, and therefore, daughter of R.