Folding stool

FIG. 1 is a perspective view of a folding stool showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a perspective view thereof, showing the folding stool in a folded state.

The broken lines shown in the drawings depict portions of the folding stool that form no part of the claimed design.