 Strategy-proofness: There does not exist a profile \(\langle R_1, R_2 , \ldots ,R_n\rangle\) in the domain of \(f\) at which \(f\) is manipulable by some individual \(i \in N\), where manipulability means the following: if \(i\) submits a false preference ordering \(R'_i\) \((\ne R_i)\), the winner is an alternative \(y'\) that \(i\) strictly prefers (according to \(R_i)\) to the alternative \(y\) that would win if \(i\) submitted the true preference ordering  \(R_i\).[8]