Equations are entered through the Equation dialog box. This appears automatically when you start the program without a data file argument, or may be brought up by clicking the Equation item on the Edit menu, or by clicking the button containing an equals sign on the toolbar.
To enter equations, simply type the first equation in the first text box. When finished, press the Enter key (or click the Add button at the bottom of the dialog box) to cause the equation to be placed in the official list of equations. The equation will be parsed, and if syntax errors are found, you will be notified. If no errors are found, the variables and parameters that have been identified will be indicated at the bottom of the dialog box. To enter another equation, just type in the top text box, as for the first equation. You may enter as many as twenty equations.
To modify an equation, you should double-click the equation that you want to change in the list box. This causes it to appear in the text box at the top of the dialog. You may change the equation at will. The backspace key deletes characters, while you may simply type to add characters at the cursor. You may move the cursor using either the arrow keys or the mouse.
If you want to delete an equation, simply select it from the list box by clicking it with the mouse, and then click the Delete button at the bottom of the dialog. When you are finished editing equations, click the Close button at the bottom of the dialog.
If you want to solve a boundary value problem for the equations you have typed in, you may check the 'Boundary Value Problem' box at the bottom of the dialog.
We are painfully aware of a bug in the program that sometimes causes it to crash. This only happens when you enter a set of equations and close the dialog box, but later open it and change the number of equations. Be assured that we are working on this.