What Is a ‘Liveness Property’ and How Does It Differ from an Invariant?

A liveness property is a condition that states "something good eventually happens," meaning the contract will eventually reach a desired state. It differs from an invariant (a safety property) which states "nothing bad ever happens." For a financial contract, a liveness property might be "a user who deposits collateral will eventually be able to withdraw it," or "the contract will eventually be upgradable." While invariants prevent loss, liveness ensures the contract remains functional and is not stuck in a permanent, unusable state.

How Does the “Nothing-at-Stake” Problem, Common in Pure PoS, Relate to PoA Security?
What Happens to the Stableswap Invariant If One of the Stablecoins Loses Its Peg Significantly?
What Is the “Gresham’s Law” Analogy in Crypto?
Why Is Arbitrage Essential for the Health and Functionality of Decentralized Exchanges?
How Does the Variance in Block Discovery Impact a Miner’s Income under PPLNS?
What Is the Relationship between an ‘Invariant’ and a ‘Safety Property’?
How Is the ‘Nothing-at-Stake’ Problem Addressed in Modern PoS Protocols?
In Derivatives, How Does a “Basis Risk” Parallel the Challenge of the Nothing-at-Stake Problem?

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