2. The apparatus of claim 1 and wherein the computer readable data structure further includes slot identifiers which identify slots within the fields, the slots being representative of positions where the user can place a cursor within the mathematical expression when the mathematical expression is displayed on the user interface.
2. The apparatus of claim 1 and wherein the computer readable data structure further includes slot identifiers which identify slots within the fields, the slots being representative of positions where the user can place a cursor within the mathematical expression when the mathematical expression is displayed on the user interface. 21. The apparatus of claim 2 and wherein the series of computer-executable instructions include a series of steps to enable the user to place a cursor within any slot via the user interface, and to thereafter select portions of the mathematical expression while the cursor remains stationary in that slot.