dx1/dt=p4-x1*p5-x1*x3*p6*(x1+p7)^-1;
dx2/dt=-x2*p9*(p10+x2)^-1-x1*p1*(x1+p3)^-1*(x2-1)*(p8-x2+1)^-1;
dx3/dt=-p13*x3*(p12+x3)^-1-x2*p2*(x3-1)*(p11-x3+1)^-1;
y1=x1;
y2=x2;
y3=x3;
x1(0)=1/100;
x2(0)=1/100;
x3(0)=1/100


