From a topological perspective, consensus requires processes to start with different inputs (e.g., 0 or 1) and agree on a single output value.
The framework distinguishes between tasks where processes are indistinguishable ("colorless") and those where they have unique identifiers. It identifies that the solvability of these tasks is determined by the of the resulting protocol complex. 2.4 Subdivision and Simplicial Maps distributed computing through combinatorial topology pdf