Let S be a set of integers and assume that l is a least element of S. If l\' is some other least element of S, then l = l\' Solution Answer : Let S be a set of integers and assume that L is a least element of S. Then for any a S we have L a . If L\' is some other least element of S, then L\' L But from our assumption , L L \' Since L\' L and L L \' so that L = L\'.