In a document in which a plurality of data items of different kinds are mixed,
when one data item is edited, the relative positional relation to other data items
is prevented from being destroyed, whereby information is prevented from becoming
meaningless or from being changed. For example, when an edit is carried out on
one data item, a deviation amount of that data item is derived and a shift process
by the same amount is effected on the other data items, whereby the relative positional
relation can be maintained among the data items.
