The ornamental design for a foldable steppingstool, as shown and described.
FIG. 1 is a front perspective view of a foldable stepping stool embodying my new design;
FIG. 2 is a bottom view of the hinge, stepping stool, and the adjustable legs;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof; and
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof;
FIG. 9 is a perspective view of the steeping stool in the unfolded use position; and,
FIG. 10 is a perspective view of the stepping stool also in the unfolded use position, with the height of the legs shown adjusted.
The evenly dashed broken lines in the drawings depict features of the foldable stepping stool, specifically a hinge, adjustments and hardware, which form no part of the claimed design. The long dash/short dash lines in FIGS. 9 and 10 depict environment and form no part of the claimed design.