To use EquationTrekkerNonModal, you first need to load the Equation Trekker Package using Needs["EquationTrekker`"].
EquationTrekkerNonModal creates a graphical interface and then returns a GUIObject object. Both the notebook and the graphical interface can interact with the kernel.
Unlike EquationTrekker, an EquationTrekkerState object is not returned when the window is closed, and the treks created by the graphical interface cannot be saved.
Although EquationTrekkerNonModal does not return an EquationTrekkerState object, it can accept one as input.
