Detailed descriptions:

extern bool echo ;

Echo flag.
If true, print an input echo.

extern bool info ;

Info flag.
If true, print informative messages.

extern bool mad8 ;

MAD-8 flag.
If true, give output in MAD-8 format.

extern Random rangen ;

Random generator.
The global random generator.

extern int seed ;

The current random seed.

extern bool tfsFormat ;

The table format flag.
If true, print tables in TFS format.

extern bool trace ;

Trace flag.
If true, print CPU time before and after each command.

extern bool verify ;

Verify flag.
If true, print warning about undefined variables.

extern bool warn ;

Warn flag.
If true, print warning messages.