Tree Felling Program Basic

x = 0
y = 0
print("Starting tree felling")
function down()
  while x > 0 do
    turtle.down()
    x = x - 1
  end
end

function next()
  turtle.turnRight()
  turtle.dig()
  turtle.forward()
  turtle.turnLeft()
  turtle.dig()
end

function treeup()
  while turtle.detect() or turtle.detectUp() do
  turtle.dig()
  turtle.digUp()
  turtle.up()
  x = x + 1
  end
end

function treedown()
  y = 0 + x
  while y > 0 do
    turtle.dig()
    turtle.digDown()
    turtle.down()
    y = y - 1
  end
  turtle.dig()
end

turtle.dig()
turtle.forward()
treeup()
next()
treedown()
print("Tree felling completed")
print("Tree was "..x.." blocks tall")