The ornamental design for a combinationtool, as shown and described.
FIG. 1 is a perspective view of a combination tool showing my new design;
FIG. 2 is a side elevation view thereof;
FIG. 3 is a top elevation view thereof;
FIG. 4 is a bottom elevation view thereof;
FIG. 5 is a rear elevation view showing the end thereof; and,
FIG. 6 is a front elevation view showing the front end of the combination tool.
Shading lines shown in the drawings are intended to represent the approximate three-dimensional contour of the design, and are not intended to indicate surface decoration.