Suppose I am writing a line (call it "line a") in the editor, compiling it, and going to see it on the viewer. Now, in the viewer, I am scrolling to another line (call it "line b") , and doing Cmd+click to go to line b in the editor. Now I want to go back to line a in the editor. How do I do that? In eclipse, and also in TexPad, there is a "go back" button. Is there a similar button on TeXShop?