mine.lua

local args = { ... }
local surface
local side

if args[1] and args[2] then
    surface = args[1]
    side = args[2]
    if math.mod(side,2) == 0 then
        side = side + 1
    end
else
    print("You must pass two args the surface y level and the dimension of the mined area")
    return nil
end

for i=1,surface - 3,1 do
    for x=1,side,1 do
        for y=1,side,1 do
            turtle.digDown()
            turtle.dig()
            if y<tonumber(side) then
                turtle.forward()
            end
        end
        if x<tonumber(side) then
            if math.mod(x,2) == 0 then
                turtle.turnRight()
                turtle.dig()
                turtle.forward()
                turtle.turnRight()
            else
                turtle.turnLeft()
                turtle.dig()
                turtle.forward()
                turtle.turnLeft()
            end
        else
            turtle.down()
            turtle.turnRight()
            for j=1,side-1,1 do
                turtle.forward()
            end
            turtle.turnRight()
            for j=1,side-1,1 do
                turtle.forward()
            end
            turtle.turnRight()
            turtle.turnRight()
        end
    end
end

for i=1,surface-3,1 do
    turtle.up()
end