nether_mine.lua

local function sideblocks()
    turtle.turnLeft()
    turtle.place()
    turtle.turnRight()
    turtle.turnRight()
    turtle.place()
    turtle.turnLeft()
end
while true do
    turtle.placeDown()
    sideblocks()
    turtle.dig()
    turtle.digUp()
    turtle.up()
    turtle.placeUp()
    sideblocks()
    turtle.dig()
    turtle.forward()
    turtle.placeUp()
    sideblocks()
    turtle.down()
end