encoding  utf-8
source
  survey map_above -title "map above"
    centerline
      data normal from to tape compass clino
        extend left
        1 2 2 0 0
        2 3 2 270 0
        3 4 2 0 0
        3 5 20 270 -10
        5 6 20 250 -10
        6 7 2  180 -70
    endcenterline
    
    
    input map_above.th2
    
    map m1 -proj extended
      s1
    endmap
    
    map m2 -proj extended
      s2
    endmap
    
    map m -proj extended
      m1
      m2 [20 0 m] above
    endmap
    
  endsurvey
endsource

select m@map_above
export map -o cave.pdf -proj extended
