& dlogtk + 0.053105*sqrts*tk)
& 18.453*dlogtk +
& 27.927*dlogtk +
& 19.334*dlogtk +
& 23.6521*dlogtk +
& (118.67*invtk - 5.977 + 1.0495 * dlogtk) *
& 23.093*dlogtk +
& (-13856*invtk + 324.57 - 47.986*dlogtk)*sqrtis +
& (35474*invtk - 771.54 + 114.723*dlogtk)*is -
_RL dlogtk
dlogtk=log(tk)
& 62.008 + 9.7944*dlogtk -