We have finished to create a modeling envrionment for creating finite state automata. Now, if we reload AToM3 and we close the ER meta-model and open the FSA meta-model:  


We can easily re-create the model that we already created:  


There are some differences between the built-in modeling environment and the one we created. Without any doubts, the appearances of the entities in our modeling environment are not exactly as they were in the other one. Also, you might have noticed that we have one button for the transition that is not present in the built-in environment. We can remove, add and modify the action of a modeling environment buttons by opening the buttons model located in the file (Close the current meta-model and open the file as a MODEL):  


So, we can delete the button "new Transition" by pressing the "delete" and then selecting the button entity on the canvas. Also, we can modify the properties of the button entity, for example changing its name to "state" (by using the Edit Entity button). You should get something like this: (Don't forget to save your model after modifying it!)  


As you may have noticed, I did not went deeply into the details of AToM3 in this tutorial (especially with programming). Its primary objective was to give an overview of modeling in AToM3 to the reader. A more advanced source of information about how AToM3 is built can be reached in Juan de Lara's tutorial.