Before revision:  \% This is due to the existence of a lower bound of \Omega(\log n) communication rounds for finding the {\em median} of 2n elements distributed evenly among two processors by Rodeh rodeh.
After revision:  (Algorithms that use only comparison operations (\leq, \geq, =) between elements to distinguish the ordering among them). This is due to the existence of a lower bound of \Omega(\log n) communication rounds for finding the {\em median} of 2n elements distributed evenly among two processors by Rodeh rodeh.