Solution Curves
> P1:= DEplot( MODEL, VAR, DOMAIN, [ IC ],
> scene=[ t, x(t) ], arrows=NONE, linecolor=BLUE ):
> P2:= DEplot( MODEL, VAR, DOMAIN, [ IC ],
> scene=[ t, y(t) ], arrows=NONE, linecolor=GREEN ):
> display( [ P1, P2 ] , title = `x and y vs. t` ); # combined solution curves
>