Sag 2x3 Mining program V4

function slice()
    while turtle.detect() do
                turtle.dig()
        end
    turtle.forward()

    while turtle.detectUp() do
                turtle.digUp()
        end

        turtle.turnLeft()
        while turtle.detect() do
                turtle.dig()
        end
    turtle.up()

        while turtle.detect() do
                turtle.dig()
        end

        turtle.turnRight()
        turtle.turnRight()

    while turtle.detect() do
                turtle.dig()
        end
    turtle.down()

        while turtle.detect() do
                turtle.dig()
        end
    turtle.turnLeft()
end

function chest()
        turtle.back()
    turtle.up()
        if turtle.detectDown() then
                turtle.digDown()
        end
        turtle.select(2)
        turtle.placeDown()
        for i = 16,3,-1 do
                turtle.select(i)
                turtle.dropDown()
        end
    turtle.down()
        turtle.forward()
end

function torch()
        turtle.select(1)
        turtle.back()
    turtle.up()
        if turtle.detectDown == false then
                turtle.placeDown()
        else
                turtle.digDown()
                turtle.placeDown()
        end
    turtle.down()
        turtle.forward()
end

print("1 = torches")
print("2 = chests")
for i=1, 640, 1 do
        if i%13 == 0 then
                torch()
        end
        if turtle.getItemCount(16) > 0 then
                chest()
        end
        slice()
end