A New XML Schema Matching Approach Using Prüfer Sequences

A method for folding and sealing sheets comprises feeding a sheet forward along a path, bulging a portion of the sheet, folding said bulged portion, adhering a portion of the sheet face to face to a portion thereof trailing backward of the fold, and passing the formed fold forward. Apparatus for folding and sealing sheets comprises means for feeding a sheet, means for bulging a portion of the sheet, means for folding the bulged portion, and means for adhering a sheet portion face to face to a portion thereof trailing the fold. Apparatus for enhancing the security of information on a front side of a sheet comprises said apparatus for folding and sealing sheets, where a plurality of folds are provided and the front side of said sheet is concealed from view inside said folds, said folds being sealed along the lateral side edge portions thereof. Address information may be applied adjacent the trailing edge of said sheet, and the trailing edge portion is folded to expose the address information to view.