dx1/dt=p1*x6*x9 - p5*x1*x10;
dx2/dt=p19*x1 - p22*x2 + p23*x3 - p6*x2*x11;
dx3/dt=p22*x2 - p23*x2 - p7*x3*x12;
dx4/dt=p2*p4^2*x8 - p8*x4*x13;
dx5/dt=p20*x4 - p24*x5 + p25*x6 - p9*x6*x14;
dx6/dt=p24*x5 - p25*x6 - p10*x6*x15;
dx7/dt=p21 - p11*x7*x16;
dx8/dt=2*x3*x8^2*(p23*x2 - p22*x2 + p7*x3*x12);
dx9/dt=x9^2*(p25*x6 - p24*x5 + p10*x6*x15);
dx10/dt=-x10^2*(p1*x6*x9 - p5*x1*x10);
dx11/dt=-x11^2*(p19*x1 - p22*x2 + p23*x3 - p6*x2*x11);
dx12/dt=x12^2*(p23*x2 - p22*x2 + p7*x3*x12);
dx13/dt=-x13^2*(p2*p4^2*x8 - p8*x4*x13);
dx14/dt=-x14^2*(p20*x4 - p24*x5 + p25*x6 - p9*x6*x14);
dx15/dt=x15^2*(p25*x6 - p24*x5 + p10*x6*x15);
dx16/dt=-x16^2*(p21 - p11*x7*x16);
y1=x1;
y2=x2;
x1(0)=0;
x2(0)=0;
x3(0)=0;
x4(0)=0;
x5(0)=0;
x6(0)=0;
x7(0)=0;
