**2. Problem Formulation**

This section defines the instance of the multi-robot exploration problem, which constitutes the basis for the proposal formulated in this work. All particular assumptions are mentioned throughout the following sections. Firstly, the environment, robot and communication models are defined. Namely, some real communication constraints are taken into account and formalised into the model. A *task* definition is given as well as the task identification method. Finally, the global exploration objectives are stated.
