Stool

FIG. 1 is a perspective view of a stool according to an embodiment of the design. FIG. 2 is a front view of the stool of FIG. 1 . FIG. 3 is a rear view of the stool of FIG. 1 . FIG. 4 is a first side view of the stool of FIG. 1 . FIG. 5 is a second side view of the stool of FIG. 1 . FIG. 6 is a top view of the stool of FIG. 1 . FIG. 7 is a bottom view of the stool of FIG. 1 . FIG. 8 is a perspective view of a stool according to another embodiment of the design. FIG. 9 is a front view of the stool of FIG. 8 . FIG. 10 is a rear view of the stool of FIG. 8 . FIG. 11 is a first side view of the stool of FIG. 8 . FIG. 12 is a second side view of the stool of FIG. 8 . FIG. 13 is a top view of the stool of FIG. 8 ; and, FIG. 14 is a bottom view of the stool of FIG. 8 . Portions of the stool shown in broken lines are for illustrative purposes only and form no part of the claimed design. The stool is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.