"property that the steps forever carry"

Film Wired on Inception’s Penrose Staircase:

"The Staircase cannot be constructed in three dimensional reality due to its property that the steps forever carry the traveler upward in a loop. The same steps are traversed, but, impossibly, after the first time around (or second, or third…) one ends up back at the beginning, and the whole journey starts again. One can turn around on the stairs and descend, as well, with the same effect—continually treading the same ground, over and over."

About the only disappointment I have with Inception is that no one uses the words "recursive occlusion". That would have been special.