anchor.diff:    use constants, only: ONE, MAX_LINE_LEN
     use error,     only: fatal_error
     use global,    only: message
  +
  +  integer, parameter :: MAX_ITERATION = 64
   
   contains
   
  
positive.code:        elseif (val < testval) then
            R = array_index
         end if
      end do
  
      array_index = L
  
negative.code:        call fatal_error()
      end if
      
      n_iteration = 0
      do while (R - L > 1)
         
         ! Check boundaries
  