HP EquationWriter - HP Exclusive Technology
With the HP EquationWriter, you can work through complicated calculations and see the equation take shape before your eyes. The HP EquationWriter displays the evolving calculation in a textbook format, so it is possible to easily compare the display to an equation on paper to ensure proper entry. And, the need to keep track of parentheses is reduced to a minimum.
The HP EquationWriter makes it quick and easy to write, edit, and mathematically manipulate formulae that would otherwise be very difficult or even impossible to do from the command line.
All commands for formula manipulation can be used, making the HP EquationWriter a full flavoured environment for work with algebraic objects.