FLP Theorem

• Async model
• Deterministic algo
• $f\leq1$

Binary consensus-problem: {0, 1}

• Bivalent: has not chosen 0 or 1
• Univalent: in any continuation will choose 1 or 0

To prove, that we can travel through only bivalent confighs

L1. Bivalent starting configuration exists

L2. Bivalent $\longrightarrow$ Bivalent

• So, we need assumptions about Time