
9: on echo;

10: off exp;

11: 
11: % a programme to calculate the surface energy tensor or the Curzon field in
11: % quasi-cylindrical coords. The surface is a cylinder x(0)=time, x(1)=azimuthal angle,
11: % x(2)=radial, x(3)=axial.
11: 
11: operator q, x, y, z;

12: for all i,j such that i neq j
12:    let {df (x (i), x(j)) => 0,
12:       df (y(i), y(j)) => 0,
12:       df (q(i), q(j)) => 0};

13: 
13: array g(3,3), gp(3,3), h(3,3), cs1(3,3,3), cs2(3,3,3),
13:    n(3), twop(2,2), two(2,2) ;

14: 


15: 
