FIG. 1 is a top plan view of a combination top sheet and fitted sheet with joining zipper, showing the top sheet for convenience of illustration.

FIG. 2 is a top view of the top sheet of FIG. 1 adjacent to a fitted sheet covering a mattress and having a mating zipper portion at a foot end of the fitted sheet. The bottom or other side of the top sheet and fitted sheet not shown is not part of the claimed design.

FIG. 3 is a rear end view of the fitted sheet of FIG. 2 covering a mattress and showing its zipper portion spaced from the zipper portion of the partial top sheet spaced therefrom.

FIG. 4 is a right side elevational view (the other side is the same view) of the top sheet shown spaced from the fitted sheet which covers a mattress.

FIG. 5 is an enlarged view of the left end portion of FIG. 4 showing the zipper portion of the top sheet adjacent to the zipper portion of the fitted sheet; and,

FIG. 6 is a perspective view thereof. The broken lines are for environmental purposes only and form no part of the claimed design.