How does arbitrageur work?
When a liquidation is proceeded, liquidation detection will be open to arbitrageurs. When arbitrageurs detected an account reach liquidation condition from off-chain data, they will be able to call the liquidation contract. Within the contract, the liquidation condition will be rechecked. Then the liquidation will be proceeded and all the position will be closed in order. The unrealized P/L will be turned to 0, the unrealized P/L of LP will also be changed through the process. If there is still margin left in the account which was liquidated, the margin will be shared equally between LP and arbitragers. If the margin left < 0, LP will pay for this loss.