teleporter /t0
  position 350 -350 10
  size 0.125 10 10
  rotation -45
  border 1
end
teleporter /t1
  position -345 345 10
  size 0.125 10 10
  rotation -45
  border 1
end
link
  from /t0:f
  to   /t1:b
end

link
  from /t0:b
  to   /t1:f
end

link
  from /t1:b
  to   /t0:f
end

link
  from /t1:f
  to   /t0:b
end

link
  from /t3:f
  to   /t2:b
end