(c) -- Phase Portrait

> IC := seq( seq( [R(0)=i/2, F(0)=j/2], j=0..4 ), i=0..5 );

> DEplot( MODEL, VAR, DOMAIN, [ IC ], WINDOW,

> scene=[ R, F ], arrows=MEDIUM, linecolor=BLUE,

> title = `Phase Portrait for # 12` );

>