 What is a strategy for a receiver? Here, it proves useful to deviate from Lewis’s original definition of the “audience’s contingency plan”. Instead, let us take a receiver’s strategy to be a function from the set of signals into the set of responses. As in the case of the sender, we allow the receiver to perform the same response for more than one signal. By symmetry, this means there are \(\mathbf{4}\) possible receiver strategies. These receiver strategies are: