Merge pull request ethereumbook#946 from HAOYUatHZ/patch-4

more on PoS

14consensus.asciidoc

@@ -28,7 +28,7 @@ Ethereum also considers switching to _ProgPOW_, a more ASIC-resistant PoW algori
 
 At the time of publication of this book, Ethereum is still using proof of work, but the ongoing research toward a proof-of-stake alternative is nearing completion. Ethereum's planned PoS algorithm is called _Casper_. The introduction of Casper as a replacement for Ethash has been postponed several times over the past two years, necessitating interventions to defuse the difficulty bomb and postpone its forced obsolescence of proof of work.
 
-In general, a PoS algorithm works as follows. The blockchain keeps track of a set of validators, and anyone who holds the blockchain's base cryptocurrency (in Ethereum's case, ether) can become a validator by sending a special type of transaction that locks up their ether into a deposit. The validators take turns proposing and voting on the next valid block, and the weight of each validator's vote depends on the size of its deposit (i.e., stake). Importantly, a validator risks losing their deposit if the block they staked it on is rejected by the majority of validators. Conversely, validators earn a small reward, proportional to their deposited stake, for every block that is accepted by the majority. Thus, PoS forces validators to act honestly and follow the consensus rules, by a system of reward and punishment. The major difference between PoS and PoW is that the punishment in PoS is intrinsic to the blockchain (e.g., loss of staked ether), whereas in PoW the punishment is extrinsic (e.g., loss of funds spent on pass:[<span class="keep-together">electricity</span>]).
+In general, a PoS algorithm works as follows. The blockchain keeps track of a set of validators, and anyone who holds the blockchain's base cryptocurrency (in Ethereum's case, ether) can become a validator by sending a special type of transaction that locks up their ether into a deposit. The validators take turns proposing and voting on the next valid block, and the weight of each validator's vote depends on the size of its deposit (i.e., stake). Importantly, a validator risks losing their deposit, i.e., "being slashed", if the block they staked it on is rejected by the majority of validators. Conversely, validators earn a small reward, proportional to their deposited stake, for every block that is accepted by the majority. Thus, PoS forces validators to act honestly and follow the consensus rules, by a system of reward and punishment. The major difference between PoS and PoW is that the punishment in PoS is intrinsic to the blockchain (e.g., loss of staked ether), whereas in PoW the punishment is extrinsic (e.g., loss of funds spent on pass:[<span class="keep-together">electricity</span>]).
 
 [[ethash]]
 === Ethash: Ethereum's Proof-of-Work Algorithm