functions in demo4.i -

             demo4  
          or demo4, mono=1  
 
     solves for the flow past a 2D airfoil using Kutta-Jakowski theory.  
     The colors represent static pressure (darker is lower pressure),  
     red lines are streamlines.  
     Solutions for various angles of attack are shown by animation.  
     With the mono=1 keyword, only the streamlines are shown.  (On a  
     monochrome terminal, the pressure makes the streamlines invisible.)