digninebynine.lua

function fwd(stp)
  for c=1,stp do
    while turtle.detect() do
     turtle.dig()
     sleep(0.25)
     end
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
  end
end

function left(stp)
 for c=1, stp do
  turtle.turnLeft()
  turtle.dig()
  turtle.forward()
  turtle.digUp()
  turtle.digDown()
 end
end

function right (stp)
 for c=1, stp do
  turtle.turnRight()
  turtle.dig()
  turtle.forward()
  turtle.digUp()
  turtle.digDown()
 end
end

function dig()
fwd(9)
for c=1,4 do
right(2)
fwd(7)
left(2)
fwd(7)
end
end

dig()