1ft, 0.5 ft, 0.25 ft, 0.124 ft etc.
Question: Will you ever reach the wall - exactly? Well no - you'll never have the distance between you and the wall = 0. But you sure will be close. Will you be within say 0.001 ft of the wall? Or say 0.000001 ft from the wall? How about where is any very small number? If so, then you can get as close as you wish or "arbitrary close."
If you want to write this mathematically then if you let n be the nth step towards the wall the the distance is
and if you want this to be less than then