Splitter Bar
The Professional license of EES provides a splitter bar on the Equations window that allows two simultaneous views of the text in the Equations window. The position of the splitter is indicated by a small red rectangle just above the scroll bar for the lower (main) window. Initially, the splitter is at its uppermost position so that only one view is available, as shown below.
Moving the cursor over the red rectangle, or anywhere on the Equations window at the same vertical position as the red rectangle, will cause the cursor to change to the splitter bar icon. To move the splitter bar, press and hold the left mouse button down when the splitter bar icon is visible and then drag the splitter bar to a new location.
Changes made in one view are immediately transferred to the other. However, when two views are available, the Undo capability is disabled.