PURPOSE: To adjust the position of subscripts and the height of parentheses by retreiving data indicating the contents of a formula to which the subscripts are imparted and calculating the height of the formula to be an object.

CONSTITUTION: The subscript 'e' is positioned by adjusting to the height of the parenthesis B1. Practically, the subscript 'e' is positioned with a line L4 for indicating the height of the parenthsis B1 as a connection line. That is, as the targeted subscript is selected by a cursor and position correction is instructed, from the structured data of the numerical formula, for instance from the data indicated by a bisecting tree, the data of the bisecting tree for which the selected subscript is the node of a top are read. A slave node is retreived for the bisecting tree, the height of the formula to be the object, that is the formula to which the subscript is imparted, for instance the formula surrounded by the parentheses B1 and B5, in this case, the height of a character 'd' is calculated, the position of the subscript 'e' is decided based on the calculated result and the allocation to the position is performed.