One way to quickly enter the text of the argument's steps is to use the insert list. It is made visible by pressing the wffs button on the symbol bar, the vertical tool bar to the left of the argument editor.
The insert list shows the well formed formulas that are the statement of the argument.
To move a wff from the list to the editor, double click on it. You can also "flip" the line by highlighting it on the list and pressing either the left or right cursor arrow. This will add the "flip" to the wff list. It can then be inserted by double clicking.
In Chapter 8, a quantified line can be instantiated and the result added to the list. Just highlight the quantified wff and press the key for the individual that is to replace the bound variable. Finally, double click on the line to be inserted into the editor.
The list itself can be moved by clicking on the bar at its top and then dragging it to a different location on top of one of the editors.