Annihilation of calcium oscillations (Muscod)

The differential equations for Annihilation of calcium oscillations in C code read as follows

rhs[0] = p[0]
         + p[1]*xd[0]
         - p[2]*xd[0]*xd[1]/(xd[0]+p[3])
         - p[4]*xd[0]*xd[2]/(xd[0]+p[5]);
 
rhs[1] = p[6]*xd[0]
         - p[7]*xd[1]/(xd[1]+p[8]);
 
rhs[2] = p[9]*xd[1]*xd[2]*xd[3]/(xd[3]+p[10])
         + p[18]*p[11]*xd[1]
         + p[12]*xd[0]
         - p[13]*xd[2]/(u[0]*xd[2]+p[14])
         - p[15]*xd[2]/(xd[2]+p[16])
         + 0.1*xd[3];
 
rhs[3] = -p[9]*xd[1]*xd[2]*xd[3]/(xd[3]+p[10])
         + p[15]*xd[2]/(xd[2]+p[16])
         - 0.1*xd[3];