None
Extracted text: let AxB= { (1,1),(1,2), (1,3),(1,4),(2,1),(2,2),(2,3), (2,4) ,(3,1),(3,2),(3,3) .(3,4),(4,1), (4,2), (4,3),(4,4)} and R= {(1,2), (2,1),(2,3),( 3,2)} then (0 1 0 0 10 10 0 10 0 0 0 0 0 1 0 0 0 100 MRm n MRm n 0 0 1 0. 0 0 0 1) a O none of them )