def merge_Fm(dfs_data):
FG = dfs_data['<STR_LIT>']<EOL>m = FG['<STR_LIT:m>']<EOL>FGm = FG[m]<EOL>FGm1 = FG[m-<NUM_LIT:1>]<EOL>if FGm[<NUM_LIT:0>]['<STR_LIT:u>'] < FGm1[<NUM_LIT:0>]['<STR_LIT:u>']:<EOL><INDENT>FGm1[<NUM_LIT:0>]['<STR_LIT:u>'] = FGm[<NUM_LIT:0>]['<STR_LIT:u>']<EOL><DEDENT>if FGm[<NUM_LIT:0>]['<STR_LIT:v>'] > FGm1[<NUM_LIT:0>]['<STR_LIT:v>']:<EOL><INDENT>FGm1[<NUM_LIT:0>]['<STR_LIT:v>'] = FGm[<NUM_LIT:0>]['<STR_LIT:v>']<EOL><DEDENT>if FGm[<NUM_LIT:1>]['<STR_LIT:x>'] < FGm1[<NUM_LIT:1>]['<STR_LIT:x>']:<EOL><INDENT>FGm1[<NUM_LIT:1>]['<STR_LIT:x>'] = FGm[<NUM_LIT:1>]['<STR_LIT:x>']<EOL><DEDENT>if FGm[<NUM_LIT:1>]['<STR_LIT:y>'] > FGm1[<NUM_LIT:1>]['<STR_LIT:y>']:<EOL><INDENT>FGm1[<NUM_LIT:1>]['<STR_LIT:y>'] = FGm[<NUM_LIT:1>]['<STR_LIT:y>']<EOL><DEDENT>del FG[m]<EOL>FG['<STR_LIT:m>'] -= <NUM_LIT:1><EOL>
Merges Fm-1 and Fm, as defined on page 19 of the paper.