\b;Instruction \c;extern\n;
The \c;extern\n; instruction  determines the \l;function\u cbot\function; that acts as main program of a robot. The name of the function declared with \c;extern\n; will apear in the program list in the lower left corner of the screen.
\c;
\s;extern void object::MowDown( )
\s;{
\s;	while ( true )
\s;	{
\s;		fire(1);
\s;		turn(10);
\s;	}
\s;}
\n;
If the program contains other functions, only the main function must be preceded by \c;extern\n;.
\c;
\s;extern void object::Square( )
\s;{
\s;	for ( int i=0 ; i<4 ; i++ )
\s;	{
\s;		Line(10);
\s;	}
\s;}
\s;
\s;void object::Line(float dist)
\s;{
\s;	move(dist);
\s;	turn(90);
\s;}
\n;
\t;See also
\l;Programming\u cbot;, \l;types\u cbot\type; and \l;categories\u cbot\category;.