For a given IDF file in energy plus, is it possible to determine the equations used in creating the model.

edit

For a given example IDF file in energy plus, is it possible to determine the equations used in creating the model. For instance, if i want to find how carbon dioxide is simulated in a particular zone, is it possible to find the the equations behind the simulation and results? If yes, where can i find such equations related to each IDF file. Any answer provided will be well appreciated. Thanks as always!