Incorrect Answer.

The formula x y (S(x,j) S(y,j) O(x,y)) Evidently, this is not expressing that one of John's sisters is older than another. (Why? E.g. what if John has no sisters?)

Note that the formula above would make more "sense" if O were interpreted as "likes", in which case the formula would say, 'All of John's sisters like each other'.
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