The Preferences menu is located in the JFLAP main menu. The picture below shows the options contained therein. Whenever a preference is changed, JFLAP will create a small file to store your choice that will be loaded every time JFLAP runs. When moving the JFLAP jar file you must also move this file, “jflapPreferences.xml.” Otherwise, your choices will be forgotten and the machine will utilize its defaults. There is no way to save files such that the empty string will always be lambda or epsilon on any other machine, since it depends on the user's preference file.
“Set the Empty String Character” will allow you to change the empty string symbol JFLAP uses. When you click on this option, the window below will appear. It allows you choose whether you wish to use lambda or epsilon for the empty string. By default, JFLAP uses lambda as the empty string.
“Enable Transitions From Turing Machine Final States” is the second choice in the menu. It allows you to toggle whether or not JFLAP will simulate Turing machines when they have final states with transitions issuing from them. By default, the transitions are not allowed, although they were in earlier versions of JFLAP. When enabled, a check will appear in the check box to the left of the choice.