Turtle Os 1.5 Mining Program

--ComputerCraft mining turtle program (CraftOS 1.5)
--For placing in a mining "corridor" and sending the turles off on strip mine branches.

--Functions
function dig()

 while turtle.detect() == true do
  turtle.dig()
  sleep (0.7)
 end

  turtle.forward()
  turtle.digUp()
  turtle.up()
  turtle.digUp()
  turtle.down()
end

function torch()

 turtle.turnLeft()
 turtle.dig()
 turtle.select(16)
 turtle.place()
 turtle.turnRight()
end

function returning()

 while turtle.detect() == true do
  turtle.dig()
  sleep (0.7)
 end

  turtle.forward()
end



function round(r,d)

local d = d or 1
 return math.floor((r + d / 2) / d * d)
end

-- Main Body --

term.write("How far would you like to mine? ")
 input = read()

 fuelreq = input * 4


  sleep (1)
 print ("Fuel Required: "..fuelreq)

  sleep (1)
 print ("Current Fuel Level: "..turtle.getFuelLevel())

local fuelshort = fuelreq - turtle.getFuelLevel()
 if turtle.getFuelLevel() - fuelreq < 0 then

 print ("Not enough fuel, please add " ..fuelshort.. " fuel into slot 1-15...")

  while turtle.getFuelLevel() < fuelreq do
   for x = 1,15 do
     turtle.select(x)
     turtle.refuel(64)
    x = x + 1
  end
 end
end

 sleep (1)
  print ("Enough fuel for this trip")

 sleep (1)
term.write ("Checking torch quantities")
sleep (0.6)
 term.write (".")
sleep (0.5)
 term.write (".")
sleep (0.5)
 print (".")
sleep (0.5)

local  torchneed = input / 10
local  torchreq = round(torchneed, 1)

turtle.select(16)

 if turtle.getItemCount(16) < torchneed then
  print ("Not enough torches, please place "..torchreq - turtle.getItemCount(16).." more into slot 16..")

  while turtle.getItemCount(16) < torchreq do
   sleep (1)
  end
 end

 sleep (0.3)
  print ("Enough torches")

 sleep (0.8)
  print ("Proceeding to mine...")

local tally = 0
 for tally = 1,input do
   dig()

  if tally % 10 == 0 then
   torch()

  end
 end

print ("Returning Back...")

 turtle.turnRight()
 turtle.turnRight()

local q = 0
 for q = 1,input do
  returning()
 end

local e = 0
 for e = 1,16 do
   turtle.select(e)
   turtle.drop(64)
  e = e + 1
 end

print ("Finished Mining!")