function dy = motif_11(t,y)
dy=zeros(3,1);
if (t >=2 & t<=4)
    y(1)=1
else 
    y(1)=0
end

if y(3)>=0.5 
    if y(1)+y(3)>=1
        dy(2)=1/(1+1)-0.5*y(2)
    else
        dy(2)=(y(1)+y(3))/(1+y(1)+y(3)) -0.5*y(2)
    end
else
    dy(2)=y(1)/(1+y(1))-0.5*y(2)
end

if y(2)>=0.5 
    if y(1)+y(2)>=1
        dy(3)=1/(1+1)-0.5*y(3)
    else
        dy(3)=(y(1)+y(2))/(1+y(1)+y(2)) -0.5*y(3)
    end
else
    dy(3)=y(1)/(1+y(1))-0.5*y(3)
end