text(Case 142, Parabolic, With Glass   
parab=t; lithyd=100; idispa=1; coval(exit,p1,0.0,0.0)
COVAL(METAL,PRPS,0.0,GLASS); difcut=0.0
  The difcut setting is necessary in order to ensure that
  the inward flow caused by the creation of the velocity
  boundary layer does not, by the operation of the hybrid
  difference scheme (difcut = 0.5, the default setting)
  cut to zero north-south diffusion link.