male(avraham)
female(sara)
parent(avraham,yzhak)
parent(sara,yzhak)
ALL (X, female(X) <=> ~male(X))
ALL (X, ALL(Y, (parent(X,Y) ^ male(X) => father(X,Y))))
ALL (X, ALL(Y, ( father(X,Y) => parent(X,Y) ^ male(X))))
ALL (X, ALL(Y, ((parent(X,Y) ^ ~father(X,Y)) => mother(X,Y))))
ALL (X, EXI(Y, (mother(X,Y)) => female(X)))