fake_x,fake_y = 1,0
x,y = -13,10
delta = {1,0}

function spiral()
    local pos = {true,true}
    pos[1] = fake_x
    pos[2] = fake_y

    if fake_x == fake_y or (fake_x < 0 and fake_x == -fake_y) or (fake_x > 0 and fake_x == 1-fake_y) then
        delta = {-delta[2], delta[1]}
    end

    fake_x = fake_x + delta[1]
    fake_y = fake_y + delta[2]
    print(fake_x .. " F " .. fake_y)
    print(delta[1] .. " D " .. delta[2])

    return pos
end

local newLocation
newLocation = spiral()
print(x + newLocation[1] .. " R " .. y + newLocation[2])
sleep(1)
newLocation = spiral()
print(x + newLocation[1] .. " R " .. y + newLocation[2])
sleep(1)
newLocation = spiral()
print(x + newLocation[1] .. " R " .. y + newLocation[2])
sleep(1)
newLocation = spiral()
print(x + newLocation[1] .. " R " .. y + newLocation[2])
sleep(1)