fi      phi     foo     Alice   Bob     Cathy	Joe
                U       C       S       S       C       C	U
Alice   S       n       n       w       o       n       n	n
Bob     C       r       r       o       n       o       n	n
Cathy	C	n	n	n	n	n	o	n
Joe     U       ox      n       n       n       n       n	o