摘要 |
<p>Stacks of superimposed paper sheets are formed from a succession of layers each of which contains a given number of groups of sheets. One or more layers which contain a first number of groups can be followed by one or more layers containing a different second number of groups so that a stack can contain layers which, in turn, contain different numbers of groups and hence different numbers of sheets. The number of sheets in each stack and in each layer is a whole multiple of the number of sheets in a group. If the average number of sheets in a series of successive stacks is to deviate from a whole multiple of the number of sheets in a group, successive stacks contain different numbers of sheets; each such number is a whole multiple of the number of sheets in a group but the total number of sheets in the series of stacks divided by the number of stacks which form the series can deviate from such whole multiple.</p> |