title "L2 SOLUTION U,XX + U + X = 0" ! begin keywords
 nodes       7 ! Number of nodes in the mesh 
 elems       6 ! Number of elements in the system
 dof         1 ! Number of unknowns per node
 el_nodes    2 ! Maximum number of nodes per element
 space       1 ! Solution space dimension
 b_rows      1 ! Number of rows in the B (operator) matrix
 shape       1 ! Element shape, 1=line, 2=tri, 3=quad, 4=hex
 remarks     7 ! Number of user remarks
 gauss       2 ! Maximum number of quadrature points
 pt_list       ! List the answers at each node point
 post_1          ! Post-processing, create n_tape1, for gradients
 post_2          ! Post-processing, create n_tape2, for norm
 exact_case 9    ! Analytic solution for list_exact, etc
 list_exact      ! List given exact answers at nodes, etc
 list_exact_flux ! List given exact fluxes at nodes, etc
 example 104     ! Analytic solution for list_exact, etc
 data_set 1      ! Data for "example" (may set exact_case)
 quit ! keyword input
U,XX + U + X = 0, U(0)=0=U(1), U = Sin(x)/Sin(1) - x            
Here we use six linear (L2) line elements.
Notes: 1) The FE solution is continuous, but the gradients
 are not continuous between elements.
2) The (negative of the) reactions give a much more accurate
 estimate of the gradients at the boundary than the value found
 by evaluating a element gradient at the boundary.
 1 1 0.            ! node, bc_flag, x
 2 0 0.166666667
 3 0 0.333333333
 4 0 0.5
 5 0 0.666666667
 6 0 0.833333334
 7 1 1.00 
    1    1    2    ! elem, two nodes
    2    2    3
    3    3    4 
    4    4    5    
    5    5    6    
    6    6    7
   1   1 0.        ! node, dof, essential value
   7   1 0.