60 40 30 / ( 120 80 60 GRIDPOINTS IN THE PAPER) 0 60 -20 20 -25 5 / (BOUNDARIES OF THE COMPUTATIONAL VOLUME) 10 / ( 27 MAXIMUM FORWARD-STAR SIZE IN THE PAPER) / 'MOD-SRC.DAT' 'MOD-REC.DAT' 'RAYS.OUT' 'END.OUT' / (SOURCE, RECEIVERS) / ' ' 'VEL.OUT' 'ICB.OUT' 'TT.OUT' 'ERR.OUT' / (INPUT AND OUTPUT FILES)