chandra, furst and lipton generalized the notion of two-party communication protocols to multi-party communication protocols. they proposed a model in which a collection of processes (formula_5) have access to a set of integers (formula_6, formula_7) except one of them, so that formula_8 is denied access to formula_9. these processes are allowed to communicate in order to arrive at a consensus on a predicate. they studied this model’s communication complexity, defined as the number of bits broadcast among all the processes. as an example, they studied the complexity of a "k"-party protocol for exactly-"n" (do all formula_9’s sum up to n?), and obtained a lower bound using the tiling method. they further applied this model to study general branching programs and obtained a time lower bound for constant-space branching programs that compute exactly-"n".