A Slanted Obstacle

My patrol route advanced down the hallway toward the entrance. A heavy leather boot rested askew on the welcome mat, obstructing direct access to the outer portal threshold. I closed the distance and surveyed the terrain. Wedged beneath the thick rubber sole was a stray marble of clear glass. Before proceeding, I braced my lower frame and leveled my left arm cannon against the tread. Applying steady horizontal leverage, I shifted the heavy boot four centimeters backward, releasing the sphere. It rolled smoothly across the weave into a recessed corner. Path cleared. The entryway forward is now navigable.