// File: @openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal initializer {
        _setOwner(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _setOwner(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal initializer {
        __Context_init_unchained();
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal initializer {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal initializer {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _setOwner(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _setOwner(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/L1/messaging/IL1CrossDomainMessenger.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";

/* Interface Imports */
import { ICrossDomainMessenger } from "../../libraries/bridge/ICrossDomainMessenger.sol";

/**
 * @title IL1CrossDomainMessenger
 */
interface IL1CrossDomainMessenger is ICrossDomainMessenger {
    /*******************
     * Data Structures *
     *******************/

    struct L2MessageInclusionProof {
        bytes32 stateRoot;
        Lib_OVMCodec.ChainBatchHeader stateRootBatchHeader;
        Lib_OVMCodec.ChainInclusionProof stateRootProof;
        bytes stateTrieWitness;
        bytes storageTrieWitness;
    }

    /********************
     * Public Functions *
     ********************/

    /**
     * Relays a cross domain message to a contract.
     * @param _target Target contract address.
     * @param _sender Message sender address.
     * @param _message Message to send to the target.
     * @param _messageNonce Nonce for the provided message.
     * @param _proof Inclusion proof for the given message.
     */
    function relayMessage(
        address _target,
        address _sender,
        bytes memory _message,
        uint256 _messageNonce,
        L2MessageInclusionProof memory _proof
    ) external;

    /**
     * Replays a cross domain message to the target messenger.
     * @param _target Target contract address.
     * @param _sender Original sender address.
     * @param _message Message to send to the target.
     * @param _queueIndex CTC Queue index for the message to replay.
     * @param _oldGasLimit Original gas limit used to send the message.
     * @param _newGasLimit New gas limit to be used for this message.
     */
    function replayMessage(
        address _target,
        address _sender,
        bytes memory _message,
        uint256 _queueIndex,
        uint32 _oldGasLimit,
        uint32 _newGasLimit
    ) external;
}

// File: contracts/L1/messaging/L1CrossDomainMessenger.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { AddressAliasHelper } from "../../standards/AddressAliasHelper.sol";
import { Lib_AddressResolver } from "../../libraries/resolver/Lib_AddressResolver.sol";
import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
import { Lib_AddressManager } from "../../libraries/resolver/Lib_AddressManager.sol";
import { Lib_SecureMerkleTrie } from "../../libraries/trie/Lib_SecureMerkleTrie.sol";
import { Lib_DefaultValues } from "../../libraries/constants/Lib_DefaultValues.sol";
import { Lib_PredeployAddresses } from "../../libraries/constants/Lib_PredeployAddresses.sol";
import { Lib_CrossDomainUtils } from "../../libraries/bridge/Lib_CrossDomainUtils.sol";

/* Interface Imports */
import { IL1CrossDomainMessenger } from "./IL1CrossDomainMessenger.sol";
import { ICanonicalTransactionChain } from "../rollup/ICanonicalTransactionChain.sol";
import { IStateCommitmentChain } from "../rollup/IStateCommitmentChain.sol";

/* External Imports */
import {
    OwnableUpgradeable
} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {
    PausableUpgradeable
} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import {
    ReentrancyGuardUpgradeable
} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

/**
 * @title L1CrossDomainMessenger
 * @dev The L1 Cross Domain Messenger contract sends messages from L1 to L2, and relays messages
 * from L2 onto L1. In the event that a message sent from L1 to L2 is rejected for exceeding the L2
 * epoch gas limit, it can be resubmitted via this contract's replay function.
 *
 * Runtime target: EVM
 */
contract L1CrossDomainMessenger is
    IL1CrossDomainMessenger,
    Lib_AddressResolver,
    OwnableUpgradeable,
    PausableUpgradeable,
    ReentrancyGuardUpgradeable
{
    /**********
     * Events *
     **********/

    event MessageBlocked(bytes32 indexed _xDomainCalldataHash);

    event MessageAllowed(bytes32 indexed _xDomainCalldataHash);

    /**********************
     * Contract Variables *
     **********************/

    mapping(bytes32 => bool) public blockedMessages;
    mapping(bytes32 => bool) public relayedMessages;
    mapping(bytes32 => bool) public successfulMessages;

    address internal xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;

    /***************
     * Constructor *
     ***************/

    /**
     * This contract is intended to be behind a delegate proxy.
     * We pass the zero address to the address resolver just to satisfy the constructor.
     * We still need to set this value in initialize().
     */
    constructor() Lib_AddressResolver(address(0)) {}

    /********************
     * Public Functions *
     ********************/

    /**
     * @param _libAddressManager Address of the Address Manager.
     */
    function initialize(address _libAddressManager) public initializer {
        require(
            address(libAddressManager) == address(0),
            "L1CrossDomainMessenger already intialized."
        );
        libAddressManager = Lib_AddressManager(_libAddressManager);
        xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;

        // Initialize upgradable OZ contracts
        __Context_init_unchained(); // Context is a dependency for both Ownable and Pausable
        __Ownable_init_unchained();
        __Pausable_init_unchained();
        __ReentrancyGuard_init_unchained();
    }

    /**
     * Pause relaying.
     */
    function pause() external onlyOwner {
        _pause();
    }

    /**
     * Block a message.
     * @param _xDomainCalldataHash Hash of the message to block.
     */
    function blockMessage(bytes32 _xDomainCalldataHash) external onlyOwner {
        blockedMessages[_xDomainCalldataHash] = true;
        emit MessageBlocked(_xDomainCalldataHash);
    }

    /**
     * Allow a message.
     * @param _xDomainCalldataHash Hash of the message to block.
     */
    function allowMessage(bytes32 _xDomainCalldataHash) external onlyOwner {
        blockedMessages[_xDomainCalldataHash] = false;
        emit MessageAllowed(_xDomainCalldataHash);
    }

    function xDomainMessageSender() public view returns (address) {
        require(
            xDomainMsgSender != Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER,
            "xDomainMessageSender is not set"
        );
        return xDomainMsgSender;
    }

    /**
     * Sends a cross domain message to the target messenger.
     * @param _target Target contract address.
     * @param _message Message to send to the target.
     * @param _gasLimit Gas limit for the provided message.
     */
    function sendMessage(
        address _target,
        bytes memory _message,
        uint32 _gasLimit
    ) public {
        address ovmCanonicalTransactionChain = resolve("CanonicalTransactionChain");
        // Use the CTC queue length as nonce
        uint40 nonce = ICanonicalTransactionChain(ovmCanonicalTransactionChain).getQueueLength();

        bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
            _target,
            msg.sender,
            _message,
            nonce
        );

        _sendXDomainMessage(ovmCanonicalTransactionChain, xDomainCalldata, _gasLimit);

        emit SentMessage(_target, msg.sender, _message, nonce, _gasLimit);
    }

    /**
     * Relays a cross domain message to a contract.
     * @inheritdoc IL1CrossDomainMessenger
     */
    function relayMessage(
        address _target,
        address _sender,
        bytes memory _message,
        uint256 _messageNonce,
        L2MessageInclusionProof memory _proof
    ) public nonReentrant whenNotPaused {
        bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
            _target,
            _sender,
            _message,
            _messageNonce
        );

        require(
            _verifyXDomainMessage(xDomainCalldata, _proof) == true,
            "Provided message could not be verified."
        );

        bytes32 xDomainCalldataHash = keccak256(xDomainCalldata);

        require(
            successfulMessages[xDomainCalldataHash] == false,
            "Provided message has already been received."
        );

        require(
            blockedMessages[xDomainCalldataHash] == false,
            "Provided message has been blocked."
        );

        require(
            _target != resolve("CanonicalTransactionChain"),
            "Cannot send L2->L1 messages to L1 system contracts."
        );

        xDomainMsgSender = _sender;
        (bool success, ) = _target.call(_message);
        xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;

        // Mark the message as received if the call was successful. Ensures that a message can be
        // relayed multiple times in the case that the call reverted.
        if (success == true) {
            successfulMessages[xDomainCalldataHash] = true;
            emit RelayedMessage(xDomainCalldataHash);
        } else {
            emit FailedRelayedMessage(xDomainCalldataHash);
        }

        // Store an identifier that can be used to prove that the given message was relayed by some
        // user. Gives us an easy way to pay relayers for their work.
        bytes32 relayId = keccak256(abi.encodePacked(xDomainCalldata, msg.sender, block.number));
        relayedMessages[relayId] = true;
    }

    /**
     * Replays a cross domain message to the target messenger.
     * @inheritdoc IL1CrossDomainMessenger
     */
    function replayMessage(
        address _target,
        address _sender,
        bytes memory _message,
        uint256 _queueIndex,
        uint32 _oldGasLimit,
        uint32 _newGasLimit
    ) public {
        // Verify that the message is in the queue:
        address canonicalTransactionChain = resolve("CanonicalTransactionChain");
        Lib_OVMCodec.QueueElement memory element = ICanonicalTransactionChain(
            canonicalTransactionChain
        ).getQueueElement(_queueIndex);

        // Compute the calldata that was originally used to send the message.
        bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
            _target,
            _sender,
            _message,
            _queueIndex
        );

        // Compute the transactionHash
        bytes32 transactionHash = keccak256(
            abi.encode(
                AddressAliasHelper.applyL1ToL2Alias(address(this)),
                Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER,
                _oldGasLimit,
                xDomainCalldata
            )
        );

        // Now check that the provided message data matches the one in the queue element.
        require(
            transactionHash == element.transactionHash,
            "Provided message has not been enqueued."
        );

        // Send the same message but with the new gas limit.
        _sendXDomainMessage(canonicalTransactionChain, xDomainCalldata, _newGasLimit);
    }

    /**********************
     * Internal Functions *
     **********************/

    /**
     * Verifies that the given message is valid.
     * @param _xDomainCalldata Calldata to verify.
     * @param _proof Inclusion proof for the message.
     * @return Whether or not the provided message is valid.
     */
    function _verifyXDomainMessage(
        bytes memory _xDomainCalldata,
        L2MessageInclusionProof memory _proof
    ) internal view returns (bool) {
        return (_verifyStateRootProof(_proof) && _verifyStorageProof(_xDomainCalldata, _proof));
    }

    /**
     * Verifies that the state root within an inclusion proof is valid.
     * @param _proof Message inclusion proof.
     * @return Whether or not the provided proof is valid.
     */
    function _verifyStateRootProof(L2MessageInclusionProof memory _proof)
        internal
        view
        returns (bool)
    {
        IStateCommitmentChain ovmStateCommitmentChain = IStateCommitmentChain(
            resolve("StateCommitmentChain")
        );

        return (ovmStateCommitmentChain.insideFraudProofWindow(_proof.stateRootBatchHeader) ==
            false &&
            ovmStateCommitmentChain.verifyStateCommitment(
                _proof.stateRoot,
                _proof.stateRootBatchHeader,
                _proof.stateRootProof
            ));
    }

    /**
     * Verifies that the storage proof within an inclusion proof is valid.
     * @param _xDomainCalldata Encoded message calldata.
     * @param _proof Message inclusion proof.
     * @return Whether or not the provided proof is valid.
     */
    function _verifyStorageProof(
        bytes memory _xDomainCalldata,
        L2MessageInclusionProof memory _proof
    ) internal view returns (bool) {
        bytes32 storageKey = keccak256(
            abi.encodePacked(
                keccak256(
                    abi.encodePacked(
                        _xDomainCalldata,
                        Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER
                    )
                ),
                uint256(0)
            )
        );

        (bool exists, bytes memory encodedMessagePassingAccount) = Lib_SecureMerkleTrie.get(
            abi.encodePacked(Lib_PredeployAddresses.L2_TO_L1_MESSAGE_PASSER),
            _proof.stateTrieWitness,
            _proof.stateRoot
        );

        require(
            exists == true,
            "Message passing predeploy has not been initialized or invalid proof provided."
        );

        Lib_OVMCodec.EVMAccount memory account = Lib_OVMCodec.decodeEVMAccount(
            encodedMessagePassingAccount
        );

        return
            Lib_SecureMerkleTrie.verifyInclusionProof(
                abi.encodePacked(storageKey),
                abi.encodePacked(uint8(1)),
                _proof.storageTrieWitness,
                account.storageRoot
            );
    }

    /**
     * Sends a cross domain message.
     * @param _canonicalTransactionChain Address of the CanonicalTransactionChain instance.
     * @param _message Message to send.
     * @param _gasLimit OVM gas limit for the message.
     */
    function _sendXDomainMessage(
        address _canonicalTransactionChain,
        bytes memory _message,
        uint256 _gasLimit
    ) internal {
        ICanonicalTransactionChain(_canonicalTransactionChain).enqueue(
            Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER,
            _gasLimit,
            _message
        );
    }
}

// File: contracts/L1/rollup/ICanonicalTransactionChain.sol



// SPDX-License-Identifier: MIT
pragma solidity >0.5.0 <0.9.0;

/* Library Imports */
import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";

/* Interface Imports */
import { IChainStorageContainer } from "./IChainStorageContainer.sol";

/**
 * @title ICanonicalTransactionChain
 */
interface ICanonicalTransactionChain {
    /**********
     * Events *
     **********/

    event L2GasParamsUpdated(
        uint256 l2GasDiscountDivisor,
        uint256 enqueueGasCost,
        uint256 enqueueL2GasPrepaid
    );

    event TransactionEnqueued(
        address indexed _l1TxOrigin,
        address indexed _target,
        uint256 _gasLimit,
        bytes _data,
        uint256 indexed _queueIndex,
        uint256 _timestamp
    );

    event QueueBatchAppended(
        uint256 _startingQueueIndex,
        uint256 _numQueueElements,
        uint256 _totalElements
    );

    event SequencerBatchAppended(
        uint256 _startingQueueIndex,
        uint256 _numQueueElements,
        uint256 _totalElements
    );

    event TransactionBatchAppended(
        uint256 indexed _batchIndex,
        bytes32 _batchRoot,
        uint256 _batchSize,
        uint256 _prevTotalElements,
        bytes _extraData
    );

    /***********
     * Structs *
     ***********/

    struct BatchContext {
        uint256 numSequencedTransactions;
        uint256 numSubsequentQueueTransactions;
        uint256 timestamp;
        uint256 blockNumber;
    }

    /*******************************
     * Authorized Setter Functions *
     *******************************/

    /**
     * Allows the Burn Admin to update the parameters which determine the amount of gas to burn.
     * The value of enqueueL2GasPrepaid is immediately updated as well.
     */
    function setGasParams(uint256 _l2GasDiscountDivisor, uint256 _enqueueGasCost) external;

    /********************
     * Public Functions *
     ********************/

    /**
     * Accesses the batch storage container.
     * @return Reference to the batch storage container.
     */
    function batches() external view returns (IChainStorageContainer);

    /**
     * Retrieves the total number of elements submitted.
     * @return _totalElements Total submitted elements.
     */
    function getTotalElements() external view returns (uint256 _totalElements);

    /**
     * Retrieves the total number of batches submitted.
     * @return _totalBatches Total submitted batches.
     */
    function getTotalBatches() external view returns (uint256 _totalBatches);

    /**
     * Returns the index of the next element to be enqueued.
     * @return Index for the next queue element.
     */
    function getNextQueueIndex() external view returns (uint40);

    /**
     * Gets the queue element at a particular index.
     * @param _index Index of the queue element to access.
     * @return _element Queue element at the given index.
     */
    function getQueueElement(uint256 _index)
        external
        view
        returns (Lib_OVMCodec.QueueElement memory _element);

    /**
     * Returns the timestamp of the last transaction.
     * @return Timestamp for the last transaction.
     */
    function getLastTimestamp() external view returns (uint40);

    /**
     * Returns the blocknumber of the last transaction.
     * @return Blocknumber for the last transaction.
     */
    function getLastBlockNumber() external view returns (uint40);

    /**
     * Get the number of queue elements which have not yet been included.
     * @return Number of pending queue elements.
     */
    function getNumPendingQueueElements() external view returns (uint40);

    /**
     * Retrieves the length of the queue, including
     * both pending and canonical transactions.
     * @return Length of the queue.
     */
    function getQueueLength() external view returns (uint40);

    /**
     * Adds a transaction to the queue.
     * @param _target Target contract to send the transaction to.
     * @param _gasLimit Gas limit for the given transaction.
     * @param _data Transaction data.
     */
    function enqueue(
        address _target,
        uint256 _gasLimit,
        bytes memory _data
    ) external;

    /**
     * Allows the sequencer to append a batch of transactions.
     * @dev This function uses a custom encoding scheme for efficiency reasons.
     * .param _shouldStartAtElement Specific batch we expect to start appending to.
     * .param _totalElementsToAppend Total number of batch elements we expect to append.
     * .param _contexts Array of batch contexts.
     * .param _transactionDataFields Array of raw transaction data.
     */
    function appendSequencerBatch(
        // uint40 _shouldStartAtElement,
        // uint24 _totalElementsToAppend,
        // BatchContext[] _contexts,
        // bytes[] _transactionDataFields
    ) external;
}

// File: contracts/L1/rollup/IChainStorageContainer.sol



// SPDX-License-Identifier: MIT
pragma solidity >0.5.0 <0.9.0;

/**
 * @title IChainStorageContainer
 */
interface IChainStorageContainer {
    /********************
     * Public Functions *
     ********************/

    /**
     * Sets the container's global metadata field. We're using `bytes27` here because we use five
     * bytes to maintain the length of the underlying data structure, meaning we have an extra
     * 27 bytes to store arbitrary data.
     * @param _globalMetadata New global metadata to set.
     */
    function setGlobalMetadata(bytes27 _globalMetadata) external;

    /**
     * Retrieves the container's global metadata field.
     * @return Container global metadata field.
     */
    function getGlobalMetadata() external view returns (bytes27);

    /**
     * Retrieves the number of objects stored in the container.
     * @return Number of objects in the container.
     */
    function length() external view returns (uint256);

    /**
     * Pushes an object into the container.
     * @param _object A 32 byte value to insert into the container.
     */
    function push(bytes32 _object) external;

    /**
     * Pushes an object into the container. Function allows setting the global metadata since
     * we'll need to touch the "length" storage slot anyway, which also contains the global
     * metadata (it's an optimization).
     * @param _object A 32 byte value to insert into the container.
     * @param _globalMetadata New global metadata for the container.
     */
    function push(bytes32 _object, bytes27 _globalMetadata) external;

    /**
     * Retrieves an object from the container.
     * @param _index Index of the particular object to access.
     * @return 32 byte object value.
     */
    function get(uint256 _index) external view returns (bytes32);

    /**
     * Removes all objects after and including a given index.
     * @param _index Object index to delete from.
     */
    function deleteElementsAfterInclusive(uint256 _index) external;

    /**
     * Removes all objects after and including a given index. Also allows setting the global
     * metadata field.
     * @param _index Object index to delete from.
     * @param _globalMetadata New global metadata for the container.
     */
    function deleteElementsAfterInclusive(uint256 _index, bytes27 _globalMetadata) external;
}

// File: contracts/L1/rollup/IStateCommitmentChain.sol



// SPDX-License-Identifier: MIT
pragma solidity >0.5.0 <0.9.0;

/* Library Imports */
import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";

/**
 * @title IStateCommitmentChain
 */
interface IStateCommitmentChain {
    /**********
     * Events *
     **********/

    event StateBatchAppended(
        uint256 indexed _batchIndex,
        bytes32 _batchRoot,
        uint256 _batchSize,
        uint256 _prevTotalElements,
        bytes _extraData
    );

    event StateBatchDeleted(uint256 indexed _batchIndex, bytes32 _batchRoot);

    /********************
     * Public Functions *
     ********************/

    /**
     * Retrieves the total number of elements submitted.
     * @return _totalElements Total submitted elements.
     */
    function getTotalElements() external view returns (uint256 _totalElements);

    /**
     * Retrieves the total number of batches submitted.
     * @return _totalBatches Total submitted batches.
     */
    function getTotalBatches() external view returns (uint256 _totalBatches);

    /**
     * Retrieves the timestamp of the last batch submitted by the sequencer.
     * @return _lastSequencerTimestamp Last sequencer batch timestamp.
     */
    function getLastSequencerTimestamp() external view returns (uint256 _lastSequencerTimestamp);

    /**
     * Appends a batch of state roots to the chain.
     * @param _batch Batch of state roots.
     * @param _shouldStartAtElement Index of the element at which this batch should start.
     */
    function appendStateBatch(bytes32[] calldata _batch, uint256 _shouldStartAtElement) external;

    /**
     * Deletes all state roots after (and including) a given batch.
     * @param _batchHeader Header of the batch to start deleting from.
     */
    function deleteStateBatch(Lib_OVMCodec.ChainBatchHeader memory _batchHeader) external;

    /**
     * Verifies a batch inclusion proof.
     * @param _element Hash of the element to verify a proof for.
     * @param _batchHeader Header of the batch in which the element was included.
     * @param _proof Merkle inclusion proof for the element.
     */
    function verifyStateCommitment(
        bytes32 _element,
        Lib_OVMCodec.ChainBatchHeader memory _batchHeader,
        Lib_OVMCodec.ChainInclusionProof memory _proof
    ) external view returns (bool _verified);

    /**
     * Checks whether a given batch is still inside its fraud proof window.
     * @param _batchHeader Header of the batch to check.
     * @return _inside Whether or not the batch is inside the fraud proof window.
     */
    function insideFraudProofWindow(Lib_OVMCodec.ChainBatchHeader memory _batchHeader)
        external
        view
        returns (bool _inside);
}

// File: contracts/libraries/bridge/ICrossDomainMessenger.sol



// SPDX-License-Identifier: MIT
pragma solidity >0.5.0 <0.9.0;

/**
 * @title ICrossDomainMessenger
 */
interface ICrossDomainMessenger {
    /**********
     * Events *
     **********/

    event SentMessage(
        address indexed target,
        address sender,
        bytes message,
        uint256 messageNonce,
        uint256 gasLimit
    );
    event RelayedMessage(bytes32 indexed msgHash);
    event FailedRelayedMessage(bytes32 indexed msgHash);

    /*************
     * Variables *
     *************/

    function xDomainMessageSender() external view returns (address);

    /********************
     * Public Functions *
     ********************/

    /**
     * Sends a cross domain message to the target messenger.
     * @param _target Target contract address.
     * @param _message Message to send to the target.
     * @param _gasLimit Gas limit for the provided message.
     */
    function sendMessage(
        address _target,
        bytes calldata _message,
        uint32 _gasLimit
    ) external;
}

// File: contracts/libraries/bridge/Lib_CrossDomainUtils.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";

/**
 * @title Lib_CrossDomainUtils
 */
library Lib_CrossDomainUtils {
    /**
     * Generates the correct cross domain calldata for a message.
     * @param _target Target contract address.
     * @param _sender Message sender address.
     * @param _message Message to send to the target.
     * @param _messageNonce Nonce for the provided message.
     * @return ABI encoded cross domain calldata.
     */
    function encodeXDomainCalldata(
        address _target,
        address _sender,
        bytes memory _message,
        uint256 _messageNonce
    ) internal pure returns (bytes memory) {
        return
            abi.encodeWithSignature(
                "relayMessage(address,address,bytes,uint256)",
                _target,
                _sender,
                _message,
                _messageNonce
            );
    }
}

// File: contracts/libraries/codec/Lib_OVMCodec.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
import { Lib_RLPWriter } from "../rlp/Lib_RLPWriter.sol";
import { Lib_BytesUtils } from "../utils/Lib_BytesUtils.sol";
import { Lib_Bytes32Utils } from "../utils/Lib_Bytes32Utils.sol";

/**
 * @title Lib_OVMCodec
 */
library Lib_OVMCodec {
    /*********
     * Enums *
     *********/

    enum QueueOrigin {
        SEQUENCER_QUEUE,
        L1TOL2_QUEUE
    }

    /***********
     * Structs *
     ***********/

    struct EVMAccount {
        uint256 nonce;
        uint256 balance;
        bytes32 storageRoot;
        bytes32 codeHash;
    }

    struct ChainBatchHeader {
        uint256 batchIndex;
        bytes32 batchRoot;
        uint256 batchSize;
        uint256 prevTotalElements;
        bytes extraData;
    }

    struct ChainInclusionProof {
        uint256 index;
        bytes32[] siblings;
    }

    struct Transaction {
        uint256 timestamp;
        uint256 blockNumber;
        QueueOrigin l1QueueOrigin;
        address l1TxOrigin;
        address entrypoint;
        uint256 gasLimit;
        bytes data;
    }

    struct TransactionChainElement {
        bool isSequenced;
        uint256 queueIndex; // QUEUED TX ONLY
        uint256 timestamp; // SEQUENCER TX ONLY
        uint256 blockNumber; // SEQUENCER TX ONLY
        bytes txData; // SEQUENCER TX ONLY
    }

    struct QueueElement {
        bytes32 transactionHash;
        uint40 timestamp;
        uint40 blockNumber;
    }

    /**********************
     * Internal Functions *
     **********************/

    /**
     * Encodes a standard OVM transaction.
     * @param _transaction OVM transaction to encode.
     * @return Encoded transaction bytes.
     */
    function encodeTransaction(Transaction memory _transaction)
        internal
        pure
        returns (bytes memory)
    {
        return
            abi.encodePacked(
                _transaction.timestamp,
                _transaction.blockNumber,
                _transaction.l1QueueOrigin,
                _transaction.l1TxOrigin,
                _transaction.entrypoint,
                _transaction.gasLimit,
                _transaction.data
            );
    }

    /**
     * Hashes a standard OVM transaction.
     * @param _transaction OVM transaction to encode.
     * @return Hashed transaction
     */
    function hashTransaction(Transaction memory _transaction) internal pure returns (bytes32) {
        return keccak256(encodeTransaction(_transaction));
    }

    /**
     * @notice Decodes an RLP-encoded account state into a useful struct.
     * @param _encoded RLP-encoded account state.
     * @return Account state struct.
     */
    function decodeEVMAccount(bytes memory _encoded) internal pure returns (EVMAccount memory) {
        Lib_RLPReader.RLPItem[] memory accountState = Lib_RLPReader.readList(_encoded);

        return
            EVMAccount({
                nonce: Lib_RLPReader.readUint256(accountState[0]),
                balance: Lib_RLPReader.readUint256(accountState[1]),
                storageRoot: Lib_RLPReader.readBytes32(accountState[2]),
                codeHash: Lib_RLPReader.readBytes32(accountState[3])
            });
    }

    /**
     * Calculates a hash for a given batch header.
     * @param _batchHeader Header to hash.
     * @return Hash of the header.
     */
    function hashBatchHeader(Lib_OVMCodec.ChainBatchHeader memory _batchHeader)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(
                    _batchHeader.batchRoot,
                    _batchHeader.batchSize,
                    _batchHeader.prevTotalElements,
                    _batchHeader.extraData
                )
            );
    }
}

// File: contracts/libraries/constants/Lib_DefaultValues.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_DefaultValues
 */
library Lib_DefaultValues {
    // The default x-domain message sender being set to a non-zero value makes
    // deployment a bit more expensive, but in exchange the refund on every call to
    // `relayMessage` by the L1 and L2 messengers will be higher.
    address internal constant DEFAULT_XDOMAIN_SENDER = 0x000000000000000000000000000000000000dEaD;
}

// File: contracts/libraries/constants/Lib_PredeployAddresses.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_PredeployAddresses
 */
library Lib_PredeployAddresses {
    address internal constant L2_TO_L1_MESSAGE_PASSER = 0x4200000000000000000000000000000000000000;
    address internal constant L1_MESSAGE_SENDER = 0x4200000000000000000000000000000000000001;
    address internal constant DEPLOYER_WHITELIST = 0x4200000000000000000000000000000000000002;
    address payable internal constant OVM_ETH = payable(0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000);
    address internal constant L2_CROSS_DOMAIN_MESSENGER =
        0x4200000000000000000000000000000000000007;
    address internal constant LIB_ADDRESS_MANAGER = 0x4200000000000000000000000000000000000008;
    address internal constant PROXY_EOA = 0x4200000000000000000000000000000000000009;
    address internal constant L2_STANDARD_BRIDGE = 0x4200000000000000000000000000000000000010;
    address internal constant SEQUENCER_FEE_WALLET = 0x4200000000000000000000000000000000000011;
    address internal constant L2_STANDARD_TOKEN_FACTORY =
        0x4200000000000000000000000000000000000012;
    address internal constant L1_BLOCK_NUMBER = 0x4200000000000000000000000000000000000013;
}

// File: contracts/libraries/resolver/Lib_AddressManager.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* External Imports */
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";

/**
 * @title Lib_AddressManager
 */
contract Lib_AddressManager is Ownable {
    /**********
     * Events *
     **********/

    event AddressSet(string indexed _name, address _newAddress, address _oldAddress);

    /*************
     * Variables *
     *************/

    mapping(bytes32 => address) private addresses;

    /********************
     * Public Functions *
     ********************/

    /**
     * Changes the address associated with a particular name.
     * @param _name String name to associate an address with.
     * @param _address Address to associate with the name.
     */
    function setAddress(string memory _name, address _address) external onlyOwner {
        bytes32 nameHash = _getNameHash(_name);
        address oldAddress = addresses[nameHash];
        addresses[nameHash] = _address;

        emit AddressSet(_name, _address, oldAddress);
    }

    /**
     * Retrieves the address associated with a given name.
     * @param _name Name to retrieve an address for.
     * @return Address associated with the given name.
     */
    function getAddress(string memory _name) external view returns (address) {
        return addresses[_getNameHash(_name)];
    }

    /**********************
     * Internal Functions *
     **********************/

    /**
     * Computes the hash of a name.
     * @param _name Name to compute a hash for.
     * @return Hash of the given name.
     */
    function _getNameHash(string memory _name) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked(_name));
    }
}

// File: contracts/libraries/resolver/Lib_AddressResolver.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_AddressManager } from "./Lib_AddressManager.sol";

/**
 * @title Lib_AddressResolver
 */
abstract contract Lib_AddressResolver {
    /*************
     * Variables *
     *************/

    Lib_AddressManager public libAddressManager;

    /***************
     * Constructor *
     ***************/

    /**
     * @param _libAddressManager Address of the Lib_AddressManager.
     */
    constructor(address _libAddressManager) {
        libAddressManager = Lib_AddressManager(_libAddressManager);
    }

    /********************
     * Public Functions *
     ********************/

    /**
     * Resolves the address associated with a given name.
     * @param _name Name to resolve an address for.
     * @return Address associated with the given name.
     */
    function resolve(string memory _name) public view returns (address) {
        return libAddressManager.getAddress(_name);
    }
}

// File: contracts/libraries/rlp/Lib_RLPReader.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_RLPReader
 * @dev Adapted from "RLPReader" by Hamdi Allam (hamdi.allam97@gmail.com).
 */
library Lib_RLPReader {
    /*************
     * Constants *
     *************/

    uint256 internal constant MAX_LIST_LENGTH = 32;

    /*********
     * Enums *
     *********/

    enum RLPItemType {
        DATA_ITEM,
        LIST_ITEM
    }

    /***********
     * Structs *
     ***********/

    struct RLPItem {
        uint256 length;
        uint256 ptr;
    }

    /**********************
     * Internal Functions *
     **********************/

    /**
     * Converts bytes to a reference to memory position and length.
     * @param _in Input bytes to convert.
     * @return Output memory reference.
     */
    function toRLPItem(bytes memory _in) internal pure returns (RLPItem memory) {
        uint256 ptr;
        assembly {
            ptr := add(_in, 32)
        }

        return RLPItem({ length: _in.length, ptr: ptr });
    }

    /**
     * Reads an RLP list value into a list of RLP items.
     * @param _in RLP list value.
     * @return Decoded RLP list items.
     */
    function readList(RLPItem memory _in) internal pure returns (RLPItem[] memory) {
        (uint256 listOffset, , RLPItemType itemType) = _decodeLength(_in);

        require(itemType == RLPItemType.LIST_ITEM, "Invalid RLP list value.");

        // Solidity in-memory arrays can't be increased in size, but *can* be decreased in size by
        // writing to the length. Since we can't know the number of RLP items without looping over
        // the entire input, we'd have to loop twice to accurately size this array. It's easier to
        // simply set a reasonable maximum list length and decrease the size before we finish.
        RLPItem[] memory out = new RLPItem[](MAX_LIST_LENGTH);

        uint256 itemCount = 0;
        uint256 offset = listOffset;
        while (offset < _in.length) {
            require(itemCount < MAX_LIST_LENGTH, "Provided RLP list exceeds max list length.");

            (uint256 itemOffset, uint256 itemLength, ) = _decodeLength(
                RLPItem({ length: _in.length - offset, ptr: _in.ptr + offset })
            );

            out[itemCount] = RLPItem({ length: itemLength + itemOffset, ptr: _in.ptr + offset });

            itemCount += 1;
            offset += itemOffset + itemLength;
        }

        // Decrease the array size to match the actual item count.
        assembly {
            mstore(out, itemCount)
        }

        return out;
    }

    /**
     * Reads an RLP list value into a list of RLP items.
     * @param _in RLP list value.
     * @return Decoded RLP list items.
     */
    function readList(bytes memory _in) internal pure returns (RLPItem[] memory) {
        return readList(toRLPItem(_in));
    }

    /**
     * Reads an RLP bytes value into bytes.
     * @param _in RLP bytes value.
     * @return Decoded bytes.
     */
    function readBytes(RLPItem memory _in) internal pure returns (bytes memory) {
        (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);

        require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes value.");

        return _copy(_in.ptr, itemOffset, itemLength);
    }

    /**
     * Reads an RLP bytes value into bytes.
     * @param _in RLP bytes value.
     * @return Decoded bytes.
     */
    function readBytes(bytes memory _in) internal pure returns (bytes memory) {
        return readBytes(toRLPItem(_in));
    }

    /**
     * Reads an RLP string value into a string.
     * @param _in RLP string value.
     * @return Decoded string.
     */
    function readString(RLPItem memory _in) internal pure returns (string memory) {
        return string(readBytes(_in));
    }

    /**
     * Reads an RLP string value into a string.
     * @param _in RLP string value.
     * @return Decoded string.
     */
    function readString(bytes memory _in) internal pure returns (string memory) {
        return readString(toRLPItem(_in));
    }

    /**
     * Reads an RLP bytes32 value into a bytes32.
     * @param _in RLP bytes32 value.
     * @return Decoded bytes32.
     */
    function readBytes32(RLPItem memory _in) internal pure returns (bytes32) {
        require(_in.length <= 33, "Invalid RLP bytes32 value.");

        (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);

        require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes32 value.");

        uint256 ptr = _in.ptr + itemOffset;
        bytes32 out;
        assembly {
            out := mload(ptr)

            // Shift the bytes over to match the item size.
            if lt(itemLength, 32) {
                out := div(out, exp(256, sub(32, itemLength)))
            }
        }

        return out;
    }

    /**
     * Reads an RLP bytes32 value into a bytes32.
     * @param _in RLP bytes32 value.
     * @return Decoded bytes32.
     */
    function readBytes32(bytes memory _in) internal pure returns (bytes32) {
        return readBytes32(toRLPItem(_in));
    }

    /**
     * Reads an RLP uint256 value into a uint256.
     * @param _in RLP uint256 value.
     * @return Decoded uint256.
     */
    function readUint256(RLPItem memory _in) internal pure returns (uint256) {
        return uint256(readBytes32(_in));
    }

    /**
     * Reads an RLP uint256 value into a uint256.
     * @param _in RLP uint256 value.
     * @return Decoded uint256.
     */
    function readUint256(bytes memory _in) internal pure returns (uint256) {
        return readUint256(toRLPItem(_in));
    }

    /**
     * Reads an RLP bool value into a bool.
     * @param _in RLP bool value.
     * @return Decoded bool.
     */
    function readBool(RLPItem memory _in) internal pure returns (bool) {
        require(_in.length == 1, "Invalid RLP boolean value.");

        uint256 ptr = _in.ptr;
        uint256 out;
        assembly {
            out := byte(0, mload(ptr))
        }

        require(out == 0 || out == 1, "Lib_RLPReader: Invalid RLP boolean value, must be 0 or 1");

        return out != 0;
    }

    /**
     * Reads an RLP bool value into a bool.
     * @param _in RLP bool value.
     * @return Decoded bool.
     */
    function readBool(bytes memory _in) internal pure returns (bool) {
        return readBool(toRLPItem(_in));
    }

    /**
     * Reads an RLP address value into a address.
     * @param _in RLP address value.
     * @return Decoded address.
     */
    function readAddress(RLPItem memory _in) internal pure returns (address) {
        if (_in.length == 1) {
            return address(0);
        }

        require(_in.length == 21, "Invalid RLP address value.");

        return address(uint160(readUint256(_in)));
    }

    /**
     * Reads an RLP address value into a address.
     * @param _in RLP address value.
     * @return Decoded address.
     */
    function readAddress(bytes memory _in) internal pure returns (address) {
        return readAddress(toRLPItem(_in));
    }

    /**
     * Reads the raw bytes of an RLP item.
     * @param _in RLP item to read.
     * @return Raw RLP bytes.
     */
    function readRawBytes(RLPItem memory _in) internal pure returns (bytes memory) {
        return _copy(_in);
    }

    /*********************
     * Private Functions *
     *********************/

    /**
     * Decodes the length of an RLP item.
     * @param _in RLP item to decode.
     * @return Offset of the encoded data.
     * @return Length of the encoded data.
     * @return RLP item type (LIST_ITEM or DATA_ITEM).
     */
    function _decodeLength(RLPItem memory _in)
        private
        pure
        returns (
            uint256,
            uint256,
            RLPItemType
        )
    {
        require(_in.length > 0, "RLP item cannot be null.");

        uint256 ptr = _in.ptr;
        uint256 prefix;
        assembly {
            prefix := byte(0, mload(ptr))
        }

        if (prefix <= 0x7f) {
            // Single byte.

            return (0, 1, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xb7) {
            // Short string.

            uint256 strLen = prefix - 0x80;

            require(_in.length > strLen, "Invalid RLP short string.");

            return (1, strLen, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xbf) {
            // Long string.
            uint256 lenOfStrLen = prefix - 0xb7;

            require(_in.length > lenOfStrLen, "Invalid RLP long string length.");

            uint256 strLen;
            assembly {
                // Pick out the string length.
                strLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfStrLen)))
            }

            require(_in.length > lenOfStrLen + strLen, "Invalid RLP long string.");

            return (1 + lenOfStrLen, strLen, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xf7) {
            // Short list.
            uint256 listLen = prefix - 0xc0;

            require(_in.length > listLen, "Invalid RLP short list.");

            return (1, listLen, RLPItemType.LIST_ITEM);
        } else {
            // Long list.
            uint256 lenOfListLen = prefix - 0xf7;

            require(_in.length > lenOfListLen, "Invalid RLP long list length.");

            uint256 listLen;
            assembly {
                // Pick out the list length.
                listLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfListLen)))
            }

            require(_in.length > lenOfListLen + listLen, "Invalid RLP long list.");

            return (1 + lenOfListLen, listLen, RLPItemType.LIST_ITEM);
        }
    }

    /**
     * Copies the bytes from a memory location.
     * @param _src Pointer to the location to read from.
     * @param _offset Offset to start reading from.
     * @param _length Number of bytes to read.
     * @return Copied bytes.
     */
    function _copy(
        uint256 _src,
        uint256 _offset,
        uint256 _length
    ) private pure returns (bytes memory) {
        bytes memory out = new bytes(_length);
        if (out.length == 0) {
            return out;
        }

        uint256 src = _src + _offset;
        uint256 dest;
        assembly {
            dest := add(out, 32)
        }

        // Copy over as many complete words as we can.
        for (uint256 i = 0; i < _length / 32; i++) {
            assembly {
                mstore(dest, mload(src))
            }

            src += 32;
            dest += 32;
        }

        // Pick out the remaining bytes.
        uint256 mask;
        unchecked {
            mask = 256**(32 - (_length % 32)) - 1;
        }

        assembly {
            mstore(dest, or(and(mload(src), not(mask)), and(mload(dest), mask)))
        }
        return out;
    }

    /**
     * Copies an RLP item into bytes.
     * @param _in RLP item to copy.
     * @return Copied bytes.
     */
    function _copy(RLPItem memory _in) private pure returns (bytes memory) {
        return _copy(_in.ptr, 0, _in.length);
    }
}

// File: contracts/libraries/rlp/Lib_RLPWriter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_RLPWriter
 * @author Bakaoh (with modifications)
 */
library Lib_RLPWriter {
    /**********************
     * Internal Functions *
     **********************/

    /**
     * RLP encodes a byte string.
     * @param _in The byte string to encode.
     * @return The RLP encoded string in bytes.
     */
    function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
        bytes memory encoded;

        if (_in.length == 1 && uint8(_in[0]) < 128) {
            encoded = _in;
        } else {
            encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
        }

        return encoded;
    }

    /**
     * RLP encodes a list of RLP encoded byte byte strings.
     * @param _in The list of RLP encoded byte strings.
     * @return The RLP encoded list of items in bytes.
     */
    function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
        bytes memory list = _flatten(_in);
        return abi.encodePacked(_writeLength(list.length, 192), list);
    }

    /**
     * RLP encodes a string.
     * @param _in The string to encode.
     * @return The RLP encoded string in bytes.
     */
    function writeString(string memory _in) internal pure returns (bytes memory) {
        return writeBytes(bytes(_in));
    }

    /**
     * RLP encodes an address.
     * @param _in The address to encode.
     * @return The RLP encoded address in bytes.
     */
    function writeAddress(address _in) internal pure returns (bytes memory) {
        return writeBytes(abi.encodePacked(_in));
    }

    /**
     * RLP encodes a uint.
     * @param _in The uint256 to encode.
     * @return The RLP encoded uint256 in bytes.
     */
    function writeUint(uint256 _in) internal pure returns (bytes memory) {
        return writeBytes(_toBinary(_in));
    }

    /**
     * RLP encodes a bool.
     * @param _in The bool to encode.
     * @return The RLP encoded bool in bytes.
     */
    function writeBool(bool _in) internal pure returns (bytes memory) {
        bytes memory encoded = new bytes(1);
        encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
        return encoded;
    }

    /*********************
     * Private Functions *
     *********************/

    /**
     * Encode the first byte, followed by the `len` in binary form if `length` is more than 55.
     * @param _len The length of the string or the payload.
     * @param _offset 128 if item is string, 192 if item is list.
     * @return RLP encoded bytes.
     */
    function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
        bytes memory encoded;

        if (_len < 56) {
            encoded = new bytes(1);
            encoded[0] = bytes1(uint8(_len) + uint8(_offset));
        } else {
            uint256 lenLen;
            uint256 i = 1;
            while (_len / i != 0) {
                lenLen++;
                i *= 256;
            }

            encoded = new bytes(lenLen + 1);
            encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
            for (i = 1; i <= lenLen; i++) {
                encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
            }
        }

        return encoded;
    }

    /**
     * Encode integer in big endian binary form with no leading zeroes.
     * @notice TODO: This should be optimized with assembly to save gas costs.
     * @param _x The integer to encode.
     * @return RLP encoded bytes.
     */
    function _toBinary(uint256 _x) private pure returns (bytes memory) {
        bytes memory b = abi.encodePacked(_x);

        uint256 i = 0;
        for (; i < 32; i++) {
            if (b[i] != 0) {
                break;
            }
        }

        bytes memory res = new bytes(32 - i);
        for (uint256 j = 0; j < res.length; j++) {
            res[j] = b[i++];
        }

        return res;
    }

    /**
     * Copies a piece of memory to another location.
     * @notice From: https://github.com/Arachnid/solidity-stringutils/blob/master/src/strings.sol.
     * @param _dest Destination location.
     * @param _src Source location.
     * @param _len Length of memory to copy.
     */
    function _memcpy(
        uint256 _dest,
        uint256 _src,
        uint256 _len
    ) private pure {
        uint256 dest = _dest;
        uint256 src = _src;
        uint256 len = _len;

        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        uint256 mask;
        unchecked {
            mask = 256**(32 - len) - 1;
        }
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /**
     * Flattens a list of byte strings into one byte string.
     * @notice From: https://github.com/sammayo/solidity-rlp-encoder/blob/master/RLPEncode.sol.
     * @param _list List of byte strings to flatten.
     * @return The flattened byte string.
     */
    function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
        if (_list.length == 0) {
            return new bytes(0);
        }

        uint256 len;
        uint256 i = 0;
        for (; i < _list.length; i++) {
            len += _list[i].length;
        }

        bytes memory flattened = new bytes(len);
        uint256 flattenedPtr;
        assembly {
            flattenedPtr := add(flattened, 0x20)
        }

        for (i = 0; i < _list.length; i++) {
            bytes memory item = _list[i];

            uint256 listPtr;
            assembly {
                listPtr := add(item, 0x20)
            }

            _memcpy(flattenedPtr, listPtr, item.length);
            flattenedPtr += _list[i].length;
        }

        return flattened;
    }
}

// File: contracts/libraries/trie/Lib_MerkleTrie.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_BytesUtils } from "../utils/Lib_BytesUtils.sol";
import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
import { Lib_RLPWriter } from "../rlp/Lib_RLPWriter.sol";

/**
 * @title Lib_MerkleTrie
 */
library Lib_MerkleTrie {
    /*******************
     * Data Structures *
     *******************/

    enum NodeType {
        BranchNode,
        ExtensionNode,
        LeafNode
    }

    struct TrieNode {
        bytes encoded;
        Lib_RLPReader.RLPItem[] decoded;
    }

    /**********************
     * Contract Constants *
     **********************/

    // TREE_RADIX determines the number of elements per branch node.
    uint256 constant TREE_RADIX = 16;
    // Branch nodes have TREE_RADIX elements plus an additional `value` slot.
    uint256 constant BRANCH_NODE_LENGTH = TREE_RADIX + 1;
    // Leaf nodes and extension nodes always have two elements, a `path` and a `value`.
    uint256 constant LEAF_OR_EXTENSION_NODE_LENGTH = 2;

    // Prefixes are prepended to the `path` within a leaf or extension node and
    // allow us to differentiate between the two node types. `ODD` or `EVEN` is
    // determined by the number of nibbles within the unprefixed `path`. If the
    // number of nibbles if even, we need to insert an extra padding nibble so
    // the resulting prefixed `path` has an even number of nibbles.
    uint8 constant PREFIX_EXTENSION_EVEN = 0;
    uint8 constant PREFIX_EXTENSION_ODD = 1;
    uint8 constant PREFIX_LEAF_EVEN = 2;
    uint8 constant PREFIX_LEAF_ODD = 3;

    // Just a utility constant. RLP represents `NULL` as 0x80.
    bytes1 constant RLP_NULL = bytes1(0x80);
    bytes constant RLP_NULL_BYTES = hex"80";
    bytes32 internal constant KECCAK256_RLP_NULL_BYTES = keccak256(RLP_NULL_BYTES);

    /**********************
     * Internal Functions *
     **********************/

    /**
     * @notice Verifies a proof that a given key/value pair is present in the
     * Merkle trie.
     * @param _key Key of the node to search for, as a hex string.
     * @param _value Value of the node to search for, as a hex string.
     * @param _proof Merkle trie inclusion proof for the desired node. Unlike
     * traditional Merkle trees, this proof is executed top-down and consists
     * of a list of RLP-encoded nodes that make a path down to the target node.
     * @param _root Known root of the Merkle trie. Used to verify that the
     * included proof is correctly constructed.
     * @return _verified `true` if the k/v pair exists in the trie, `false` otherwise.
     */
    function verifyInclusionProof(
        bytes memory _key,
        bytes memory _value,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bool _verified) {
        (bool exists, bytes memory value) = get(_key, _proof, _root);

        return (exists && Lib_BytesUtils.equal(_value, value));
    }

    /**
     * @notice Updates a Merkle trie and returns a new root hash.
     * @param _key Key of the node to update, as a hex string.
     * @param _value Value of the node to update, as a hex string.
     * @param _proof Merkle trie inclusion proof for the node *nearest* the
     * target node. If the key exists, we can simply update the value.
     * Otherwise, we need to modify the trie to handle the new k/v pair.
     * @param _root Known root of the Merkle trie. Used to verify that the
     * included proof is correctly constructed.
     * @return _updatedRoot Root hash of the newly constructed trie.
     */
    function update(
        bytes memory _key,
        bytes memory _value,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bytes32 _updatedRoot) {
        // Special case when inserting the very first node.
        if (_root == KECCAK256_RLP_NULL_BYTES) {
            return getSingleNodeRootHash(_key, _value);
        }

        TrieNode[] memory proof = _parseProof(_proof);
        (uint256 pathLength, bytes memory keyRemainder, ) = _walkNodePath(proof, _key, _root);
        TrieNode[] memory newPath = _getNewPath(proof, pathLength, _key, keyRemainder, _value);

        return _getUpdatedTrieRoot(newPath, _key);
    }

    /**
     * @notice Retrieves the value associated with a given key.
     * @param _key Key to search for, as hex bytes.
     * @param _proof Merkle trie inclusion proof for the key.
     * @param _root Known root of the Merkle trie.
     * @return _exists Whether or not the key exists.
     * @return _value Value of the key if it exists.
     */
    function get(
        bytes memory _key,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bool _exists, bytes memory _value) {
        TrieNode[] memory proof = _parseProof(_proof);
        (uint256 pathLength, bytes memory keyRemainder, bool isFinalNode) = _walkNodePath(
            proof,
            _key,
            _root
        );

        bool exists = keyRemainder.length == 0;

        require(exists || isFinalNode, "Provided proof is invalid.");

        bytes memory value = exists ? _getNodeValue(proof[pathLength - 1]) : bytes("");

        return (exists, value);
    }

    /**
     * Computes the root hash for a trie with a single node.
     * @param _key Key for the single node.
     * @param _value Value for the single node.
     * @return _updatedRoot Hash of the trie.
     */
    function getSingleNodeRootHash(bytes memory _key, bytes memory _value)
        internal
        pure
        returns (bytes32 _updatedRoot)
    {
        return keccak256(_makeLeafNode(Lib_BytesUtils.toNibbles(_key), _value).encoded);
    }

    /*********************
     * Private Functions *
     *********************/

    /**
     * @notice Walks through a proof using a provided key.
     * @param _proof Inclusion proof to walk through.
     * @param _key Key to use for the walk.
     * @param _root Known root of the trie.
     * @return _pathLength Length of the final path
     * @return _keyRemainder Portion of the key remaining after the walk.
     * @return _isFinalNode Whether or not we've hit a dead end.
     */
    function _walkNodePath(
        TrieNode[] memory _proof,
        bytes memory _key,
        bytes32 _root
    )
        private
        pure
        returns (
            uint256 _pathLength,
            bytes memory _keyRemainder,
            bool _isFinalNode
        )
    {
        uint256 pathLength = 0;
        bytes memory key = Lib_BytesUtils.toNibbles(_key);

        bytes32 currentNodeID = _root;
        uint256 currentKeyIndex = 0;
        uint256 currentKeyIncrement = 0;
        TrieNode memory currentNode;

        // Proof is top-down, so we start at the first element (root).
        for (uint256 i = 0; i < _proof.length; i++) {
            currentNode = _proof[i];
            currentKeyIndex += currentKeyIncrement;

            // Keep track of the proof elements we actually need.
            // It's expensive to resize arrays, so this simply reduces gas costs.
            pathLength += 1;

            if (currentKeyIndex == 0) {
                // First proof element is always the root node.
                require(keccak256(currentNode.encoded) == currentNodeID, "Invalid root hash");
            } else if (currentNode.encoded.length >= 32) {
                // Nodes 32 bytes or larger are hashed inside branch nodes.
                require(
                    keccak256(currentNode.encoded) == currentNodeID,
                    "Invalid large internal hash"
                );
            } else {
                // Nodes smaller than 31 bytes aren't hashed.
                require(
                    Lib_BytesUtils.toBytes32(currentNode.encoded) == currentNodeID,
                    "Invalid internal node hash"
                );
            }

            if (currentNode.decoded.length == BRANCH_NODE_LENGTH) {
                if (currentKeyIndex == key.length) {
                    // We've hit the end of the key
                    // meaning the value should be within this branch node.
                    break;
                } else {
                    // We're not at the end of the key yet.
                    // Figure out what the next node ID should be and continue.
                    uint8 branchKey = uint8(key[currentKeyIndex]);
                    Lib_RLPReader.RLPItem memory nextNode = currentNode.decoded[branchKey];
                    currentNodeID = _getNodeID(nextNode);
                    currentKeyIncrement = 1;
                    continue;
                }
            } else if (currentNode.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
                bytes memory path = _getNodePath(currentNode);
                uint8 prefix = uint8(path[0]);
                uint8 offset = 2 - (prefix % 2);
                bytes memory pathRemainder = Lib_BytesUtils.slice(path, offset);
                bytes memory keyRemainder = Lib_BytesUtils.slice(key, currentKeyIndex);
                uint256 sharedNibbleLength = _getSharedNibbleLength(pathRemainder, keyRemainder);

                if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                    if (
                        pathRemainder.length == sharedNibbleLength &&
                        keyRemainder.length == sharedNibbleLength
                    ) {
                        // The key within this leaf matches our key exactly.
                        // Increment the key index to reflect that we have no remainder.
                        currentKeyIndex += sharedNibbleLength;
                    }

                    // We've hit a leaf node, so our next node should be NULL.
                    currentNodeID = bytes32(RLP_NULL);
                    break;
                } else if (prefix == PREFIX_EXTENSION_EVEN || prefix == PREFIX_EXTENSION_ODD) {
                    if (sharedNibbleLength != pathRemainder.length) {
                        // Our extension node is not identical to the remainder.
                        // We've hit the end of this path
                        // updates will need to modify this extension.
                        currentNodeID = bytes32(RLP_NULL);
                        break;
                    } else {
                        // Our extension shares some nibbles.
                        // Carry on to the next node.
                        currentNodeID = _getNodeID(currentNode.decoded[1]);
                        currentKeyIncrement = sharedNibbleLength;
                        continue;
                    }
                } else {
                    revert("Received a node with an unknown prefix");
                }
            } else {
                revert("Received an unparseable node.");
            }
        }

        // If our node ID is NULL, then we're at a dead end.
        bool isFinalNode = currentNodeID == bytes32(RLP_NULL);
        return (pathLength, Lib_BytesUtils.slice(key, currentKeyIndex), isFinalNode);
    }

    /**
     * @notice Creates new nodes to support a k/v pair insertion into a given Merkle trie path.
     * @param _path Path to the node nearest the k/v pair.
     * @param _pathLength Length of the path. Necessary because the provided path may include
     *  additional nodes (e.g., it comes directly from a proof) and we can't resize in-memory
     *  arrays without costly duplication.
     * @param _key Full original key.
     * @param _keyRemainder Portion of the initial key that must be inserted into the trie.
     * @param _value Value to insert at the given key.
     * @return _newPath A new path with the inserted k/v pair and extra supporting nodes.
     */
    function _getNewPath(
        TrieNode[] memory _path,
        uint256 _pathLength,
        bytes memory _key,
        bytes memory _keyRemainder,
        bytes memory _value
    ) private pure returns (TrieNode[] memory _newPath) {
        bytes memory keyRemainder = _keyRemainder;

        // Most of our logic depends on the status of the last node in the path.
        TrieNode memory lastNode = _path[_pathLength - 1];
        NodeType lastNodeType = _getNodeType(lastNode);

        // Create an array for newly created nodes.
        // We need up to three new nodes, depending on the contents of the last node.
        // Since array resizing is expensive, we'll keep track of the size manually.
        // We're using an explicit `totalNewNodes += 1` after insertions for clarity.
        TrieNode[] memory newNodes = new TrieNode[](3);
        uint256 totalNewNodes = 0;

        // solhint-disable-next-line max-line-length
        // Reference: https://github.com/ethereumjs/merkle-patricia-tree/blob/c0a10395aab37d42c175a47114ebfcbd7efcf059/src/baseTrie.ts#L294-L313
        bool matchLeaf = false;
        if (lastNodeType == NodeType.LeafNode) {
            uint256 l = 0;
            if (_path.length > 0) {
                for (uint256 i = 0; i < _path.length - 1; i++) {
                    if (_getNodeType(_path[i]) == NodeType.BranchNode) {
                        l++;
                    } else {
                        l += _getNodeKey(_path[i]).length;
                    }
                }
            }

            if (
                _getSharedNibbleLength(
                    _getNodeKey(lastNode),
                    Lib_BytesUtils.slice(Lib_BytesUtils.toNibbles(_key), l)
                ) ==
                _getNodeKey(lastNode).length &&
                keyRemainder.length == 0
            ) {
                matchLeaf = true;
            }
        }

        if (matchLeaf) {
            // We've found a leaf node with the given key.
            // Simply need to update the value of the node to match.
            newNodes[totalNewNodes] = _makeLeafNode(_getNodeKey(lastNode), _value);
            totalNewNodes += 1;
        } else if (lastNodeType == NodeType.BranchNode) {
            if (keyRemainder.length == 0) {
                // We've found a branch node with the given key.
                // Simply need to update the value of the node to match.
                newNodes[totalNewNodes] = _editBranchValue(lastNode, _value);
                totalNewNodes += 1;
            } else {
                // We've found a branch node, but it doesn't contain our key.
                // Reinsert the old branch for now.
                newNodes[totalNewNodes] = lastNode;
                totalNewNodes += 1;
                // Create a new leaf node, slicing our remainder since the first byte points
                // to our branch node.
                newNodes[totalNewNodes] = _makeLeafNode(
                    Lib_BytesUtils.slice(keyRemainder, 1),
                    _value
                );
                totalNewNodes += 1;
            }
        } else {
            // Our last node is either an extension node or a leaf node with a different key.
            bytes memory lastNodeKey = _getNodeKey(lastNode);
            uint256 sharedNibbleLength = _getSharedNibbleLength(lastNodeKey, keyRemainder);

            if (sharedNibbleLength != 0) {
                // We've got some shared nibbles between the last node and our key remainder.
                // We'll need to insert an extension node that covers these shared nibbles.
                bytes memory nextNodeKey = Lib_BytesUtils.slice(lastNodeKey, 0, sharedNibbleLength);
                newNodes[totalNewNodes] = _makeExtensionNode(nextNodeKey, _getNodeHash(_value));
                totalNewNodes += 1;

                // Cut down the keys since we've just covered these shared nibbles.
                lastNodeKey = Lib_BytesUtils.slice(lastNodeKey, sharedNibbleLength);
                keyRemainder = Lib_BytesUtils.slice(keyRemainder, sharedNibbleLength);
            }

            // Create an empty branch to fill in.
            TrieNode memory newBranch = _makeEmptyBranchNode();

            if (lastNodeKey.length == 0) {
                // Key remainder was larger than the key for our last node.
                // The value within our last node is therefore going to be shifted into
                // a branch value slot.
                newBranch = _editBranchValue(newBranch, _getNodeValue(lastNode));
            } else {
                // Last node key was larger than the key remainder.
                // We're going to modify some index of our branch.
                uint8 branchKey = uint8(lastNodeKey[0]);
                // Move on to the next nibble.
                lastNodeKey = Lib_BytesUtils.slice(lastNodeKey, 1);

                if (lastNodeType == NodeType.LeafNode) {
                    // We're dealing with a leaf node.
                    // We'll modify the key and insert the old leaf node into the branch index.
                    TrieNode memory modifiedLastNode = _makeLeafNode(
                        lastNodeKey,
                        _getNodeValue(lastNode)
                    );
                    newBranch = _editBranchIndex(
                        newBranch,
                        branchKey,
                        _getNodeHash(modifiedLastNode.encoded)
                    );
                } else if (lastNodeKey.length != 0) {
                    // We're dealing with a shrinking extension node.
                    // We need to modify the node to decrease the size of the key.
                    TrieNode memory modifiedLastNode = _makeExtensionNode(
                        lastNodeKey,
                        _getNodeValue(lastNode)
                    );
                    newBranch = _editBranchIndex(
                        newBranch,
                        branchKey,
                        _getNodeHash(modifiedLastNode.encoded)
                    );
                } else {
                    // We're dealing with an unnecessary extension node.
                    // We're going to delete the node entirely.
                    // Simply insert its current value into the branch index.
                    newBranch = _editBranchIndex(newBranch, branchKey, _getNodeValue(lastNode));
                }
            }

            if (keyRemainder.length == 0) {
                // We've got nothing left in the key remainder.
                // Simply insert the value into the branch value slot.
                newBranch = _editBranchValue(newBranch, _value);
                // Push the branch into the list of new nodes.
                newNodes[totalNewNodes] = newBranch;
                totalNewNodes += 1;
            } else {
                // We've got some key remainder to work with.
                // We'll be inserting a leaf node into the trie.
                // First, move on to the next nibble.
                keyRemainder = Lib_BytesUtils.slice(keyRemainder, 1);
                // Push the branch into the list of new nodes.
                newNodes[totalNewNodes] = newBranch;
                totalNewNodes += 1;
                // Push a new leaf node for our k/v pair.
                newNodes[totalNewNodes] = _makeLeafNode(keyRemainder, _value);
                totalNewNodes += 1;
            }
        }

        // Finally, join the old path with our newly created nodes.
        // Since we're overwriting the last node in the path, we use `_pathLength - 1`.
        return _joinNodeArrays(_path, _pathLength - 1, newNodes, totalNewNodes);
    }

    /**
     * @notice Computes the trie root from a given path.
     * @param _nodes Path to some k/v pair.
     * @param _key Key for the k/v pair.
     * @return _updatedRoot Root hash for the updated trie.
     */
    function _getUpdatedTrieRoot(TrieNode[] memory _nodes, bytes memory _key)
        private
        pure
        returns (bytes32 _updatedRoot)
    {
        bytes memory key = Lib_BytesUtils.toNibbles(_key);

        // Some variables to keep track of during iteration.
        TrieNode memory currentNode;
        NodeType currentNodeType;
        bytes memory previousNodeHash;

        // Run through the path backwards to rebuild our root hash.
        for (uint256 i = _nodes.length; i > 0; i--) {
            // Pick out the current node.
            currentNode = _nodes[i - 1];
            currentNodeType = _getNodeType(currentNode);

            if (currentNodeType == NodeType.LeafNode) {
                // Leaf nodes are already correctly encoded.
                // Shift the key over to account for the nodes key.
                bytes memory nodeKey = _getNodeKey(currentNode);
                key = Lib_BytesUtils.slice(key, 0, key.length - nodeKey.length);
            } else if (currentNodeType == NodeType.ExtensionNode) {
                // Shift the key over to account for the nodes key.
                bytes memory nodeKey = _getNodeKey(currentNode);
                key = Lib_BytesUtils.slice(key, 0, key.length - nodeKey.length);

                // If this node is the last element in the path, it'll be correctly encoded
                // and we can skip this part.
                if (previousNodeHash.length > 0) {
                    // Re-encode the node based on the previous node.
                    currentNode = _editExtensionNodeValue(currentNode, previousNodeHash);
                }
            } else if (currentNodeType == NodeType.BranchNode) {
                // If this node is the last element in the path, it'll be correctly encoded
                // and we can skip this part.
                if (previousNodeHash.length > 0) {
                    // Re-encode the node based on the previous node.
                    uint8 branchKey = uint8(key[key.length - 1]);
                    key = Lib_BytesUtils.slice(key, 0, key.length - 1);
                    currentNode = _editBranchIndex(currentNode, branchKey, previousNodeHash);
                }
            }

            // Compute the node hash for the next iteration.
            previousNodeHash = _getNodeHash(currentNode.encoded);
        }

        // Current node should be the root at this point.
        // Simply return the hash of its encoding.
        return keccak256(currentNode.encoded);
    }

    /**
     * @notice Parses an RLP-encoded proof into something more useful.
     * @param _proof RLP-encoded proof to parse.
     * @return _parsed Proof parsed into easily accessible structs.
     */
    function _parseProof(bytes memory _proof) private pure returns (TrieNode[] memory _parsed) {
        Lib_RLPReader.RLPItem[] memory nodes = Lib_RLPReader.readList(_proof);
        TrieNode[] memory proof = new TrieNode[](nodes.length);

        for (uint256 i = 0; i < nodes.length; i++) {
            bytes memory encoded = Lib_RLPReader.readBytes(nodes[i]);
            proof[i] = TrieNode({ encoded: encoded, decoded: Lib_RLPReader.readList(encoded) });
        }

        return proof;
    }

    /**
     * @notice Picks out the ID for a node. Node ID is referred to as the
     * "hash" within the specification, but nodes < 32 bytes are not actually
     * hashed.
     * @param _node Node to pull an ID for.
     * @return _nodeID ID for the node, depending on the size of its contents.
     */
    function _getNodeID(Lib_RLPReader.RLPItem memory _node) private pure returns (bytes32 _nodeID) {
        bytes memory nodeID;

        if (_node.length < 32) {
            // Nodes smaller than 32 bytes are RLP encoded.
            nodeID = Lib_RLPReader.readRawBytes(_node);
        } else {
            // Nodes 32 bytes or larger are hashed.
            nodeID = Lib_RLPReader.readBytes(_node);
        }

        return Lib_BytesUtils.toBytes32(nodeID);
    }

    /**
     * @notice Gets the path for a leaf or extension node.
     * @param _node Node to get a path for.
     * @return _path Node path, converted to an array of nibbles.
     */
    function _getNodePath(TrieNode memory _node) private pure returns (bytes memory _path) {
        return Lib_BytesUtils.toNibbles(Lib_RLPReader.readBytes(_node.decoded[0]));
    }

    /**
     * @notice Gets the key for a leaf or extension node. Keys are essentially
     * just paths without any prefix.
     * @param _node Node to get a key for.
     * @return _key Node key, converted to an array of nibbles.
     */
    function _getNodeKey(TrieNode memory _node) private pure returns (bytes memory _key) {
        return _removeHexPrefix(_getNodePath(_node));
    }

    /**
     * @notice Gets the path for a node.
     * @param _node Node to get a value for.
     * @return _value Node value, as hex bytes.
     */
    function _getNodeValue(TrieNode memory _node) private pure returns (bytes memory _value) {
        return Lib_RLPReader.readBytes(_node.decoded[_node.decoded.length - 1]);
    }

    /**
     * @notice Computes the node hash for an encoded node. Nodes < 32 bytes
     * are not hashed, all others are keccak256 hashed.
     * @param _encoded Encoded node to hash.
     * @return _hash Hash of the encoded node. Simply the input if < 32 bytes.
     */
    function _getNodeHash(bytes memory _encoded) private pure returns (bytes memory _hash) {
        if (_encoded.length < 32) {
            return _encoded;
        } else {
            return abi.encodePacked(keccak256(_encoded));
        }
    }

    /**
     * @notice Determines the type for a given node.
     * @param _node Node to determine a type for.
     * @return _type Type of the node; BranchNode/ExtensionNode/LeafNode.
     */
    function _getNodeType(TrieNode memory _node) private pure returns (NodeType _type) {
        if (_node.decoded.length == BRANCH_NODE_LENGTH) {
            return NodeType.BranchNode;
        } else if (_node.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
            bytes memory path = _getNodePath(_node);
            uint8 prefix = uint8(path[0]);

            if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                return NodeType.LeafNode;
            } else if (prefix == PREFIX_EXTENSION_EVEN || prefix == PREFIX_EXTENSION_ODD) {
                return NodeType.ExtensionNode;
            }
        }

        revert("Invalid node type");
    }

    /**
     * @notice Utility; determines the number of nibbles shared between two
     * nibble arrays.
     * @param _a First nibble array.
     * @param _b Second nibble array.
     * @return _shared Number of shared nibbles.
     */
    function _getSharedNibbleLength(bytes memory _a, bytes memory _b)
        private
        pure
        returns (uint256 _shared)
    {
        uint256 i = 0;
        while (_a.length > i && _b.length > i && _a[i] == _b[i]) {
            i++;
        }
        return i;
    }

    /**
     * @notice Utility; converts an RLP-encoded node into our nice struct.
     * @param _raw RLP-encoded node to convert.
     * @return _node Node as a TrieNode struct.
     */
    function _makeNode(bytes[] memory _raw) private pure returns (TrieNode memory _node) {
        bytes memory encoded = Lib_RLPWriter.writeList(_raw);

        return TrieNode({ encoded: encoded, decoded: Lib_RLPReader.readList(encoded) });
    }

    /**
     * @notice Utility; converts an RLP-decoded node into our nice struct.
     * @param _items RLP-decoded node to convert.
     * @return _node Node as a TrieNode struct.
     */
    function _makeNode(Lib_RLPReader.RLPItem[] memory _items)
        private
        pure
        returns (TrieNode memory _node)
    {
        bytes[] memory raw = new bytes[](_items.length);
        for (uint256 i = 0; i < _items.length; i++) {
            raw[i] = Lib_RLPReader.readRawBytes(_items[i]);
        }
        return _makeNode(raw);
    }

    /**
     * @notice Creates a new extension node.
     * @param _key Key for the extension node, unprefixed.
     * @param _value Value for the extension node.
     * @return _node New extension node with the given k/v pair.
     */
    function _makeExtensionNode(bytes memory _key, bytes memory _value)
        private
        pure
        returns (TrieNode memory _node)
    {
        bytes[] memory raw = new bytes[](2);
        bytes memory key = _addHexPrefix(_key, false);
        raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
        raw[1] = Lib_RLPWriter.writeBytes(_value);
        return _makeNode(raw);
    }

    /**
     * Creates a new extension node with the same key but a different value.
     * @param _node Extension node to copy and modify.
     * @param _value New value for the extension node.
     * @return New node with the same key and different value.
     */
    function _editExtensionNodeValue(TrieNode memory _node, bytes memory _value)
        private
        pure
        returns (TrieNode memory)
    {
        bytes[] memory raw = new bytes[](2);
        bytes memory key = _addHexPrefix(_getNodeKey(_node), false);
        raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
        if (_value.length < 32) {
            raw[1] = _value;
        } else {
            raw[1] = Lib_RLPWriter.writeBytes(_value);
        }
        return _makeNode(raw);
    }

    /**
     * @notice Creates a new leaf node.
     * @dev This function is essentially identical to `_makeExtensionNode`.
     * Although we could route both to a single method with a flag, it's
     * more gas efficient to keep them separate and duplicate the logic.
     * @param _key Key for the leaf node, unprefixed.
     * @param _value Value for the leaf node.
     * @return _node New leaf node with the given k/v pair.
     */
    function _makeLeafNode(bytes memory _key, bytes memory _value)
        private
        pure
        returns (TrieNode memory _node)
    {
        bytes[] memory raw = new bytes[](2);
        bytes memory key = _addHexPrefix(_key, true);
        raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
        raw[1] = Lib_RLPWriter.writeBytes(_value);
        return _makeNode(raw);
    }

    /**
     * @notice Creates an empty branch node.
     * @return _node Empty branch node as a TrieNode struct.
     */
    function _makeEmptyBranchNode() private pure returns (TrieNode memory _node) {
        bytes[] memory raw = new bytes[](BRANCH_NODE_LENGTH);
        for (uint256 i = 0; i < raw.length; i++) {
            raw[i] = RLP_NULL_BYTES;
        }
        return _makeNode(raw);
    }

    /**
     * @notice Modifies the value slot for a given branch.
     * @param _branch Branch node to modify.
     * @param _value Value to insert into the branch.
     * @return _updatedNode Modified branch node.
     */
    function _editBranchValue(TrieNode memory _branch, bytes memory _value)
        private
        pure
        returns (TrieNode memory _updatedNode)
    {
        bytes memory encoded = Lib_RLPWriter.writeBytes(_value);
        _branch.decoded[_branch.decoded.length - 1] = Lib_RLPReader.toRLPItem(encoded);
        return _makeNode(_branch.decoded);
    }

    /**
     * @notice Modifies a slot at an index for a given branch.
     * @param _branch Branch node to modify.
     * @param _index Slot index to modify.
     * @param _value Value to insert into the slot.
     * @return _updatedNode Modified branch node.
     */
    function _editBranchIndex(
        TrieNode memory _branch,
        uint8 _index,
        bytes memory _value
    ) private pure returns (TrieNode memory _updatedNode) {
        bytes memory encoded = _value.length < 32 ? _value : Lib_RLPWriter.writeBytes(_value);
        _branch.decoded[_index] = Lib_RLPReader.toRLPItem(encoded);
        return _makeNode(_branch.decoded);
    }

    /**
     * @notice Utility; adds a prefix to a key.
     * @param _key Key to prefix.
     * @param _isLeaf Whether or not the key belongs to a leaf.
     * @return _prefixedKey Prefixed key.
     */
    function _addHexPrefix(bytes memory _key, bool _isLeaf)
        private
        pure
        returns (bytes memory _prefixedKey)
    {
        uint8 prefix = _isLeaf ? uint8(0x02) : uint8(0x00);
        uint8 offset = uint8(_key.length % 2);
        bytes memory prefixed = new bytes(2 - offset);
        prefixed[0] = bytes1(prefix + offset);
        return abi.encodePacked(prefixed, _key);
    }

    /**
     * @notice Utility; removes a prefix from a path.
     * @param _path Path to remove the prefix from.
     * @return _unprefixedKey Unprefixed key.
     */
    function _removeHexPrefix(bytes memory _path)
        private
        pure
        returns (bytes memory _unprefixedKey)
    {
        if (uint8(_path[0]) % 2 == 0) {
            return Lib_BytesUtils.slice(_path, 2);
        } else {
            return Lib_BytesUtils.slice(_path, 1);
        }
    }

    /**
     * @notice Utility; combines two node arrays. Array lengths are required
     * because the actual lengths may be longer than the filled lengths.
     * Array resizing is extremely costly and should be avoided.
     * @param _a First array to join.
     * @param _aLength Length of the first array.
     * @param _b Second array to join.
     * @param _bLength Length of the second array.
     * @return _joined Combined node array.
     */
    function _joinNodeArrays(
        TrieNode[] memory _a,
        uint256 _aLength,
        TrieNode[] memory _b,
        uint256 _bLength
    ) private pure returns (TrieNode[] memory _joined) {
        TrieNode[] memory ret = new TrieNode[](_aLength + _bLength);

        // Copy elements from the first array.
        for (uint256 i = 0; i < _aLength; i++) {
            ret[i] = _a[i];
        }

        // Copy elements from the second array.
        for (uint256 i = 0; i < _bLength; i++) {
            ret[i + _aLength] = _b[i];
        }

        return ret;
    }
}

// File: contracts/libraries/trie/Lib_SecureMerkleTrie.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/* Library Imports */
import { Lib_MerkleTrie } from "./Lib_MerkleTrie.sol";

/**
 * @title Lib_SecureMerkleTrie
 */
library Lib_SecureMerkleTrie {
    /**********************
     * Internal Functions *
     **********************/

    /**
     * @notice Verifies a proof that a given key/value pair is present in the
     * Merkle trie.
     * @param _key Key of the node to search for, as a hex string.
     * @param _value Value of the node to search for, as a hex string.
     * @param _proof Merkle trie inclusion proof for the desired node. Unlike
     * traditional Merkle trees, this proof is executed top-down and consists
     * of a list of RLP-encoded nodes that make a path down to the target node.
     * @param _root Known root of the Merkle trie. Used to verify that the
     * included proof is correctly constructed.
     * @return _verified `true` if the k/v pair exists in the trie, `false` otherwise.
     */
    function verifyInclusionProof(
        bytes memory _key,
        bytes memory _value,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bool _verified) {
        bytes memory key = _getSecureKey(_key);
        return Lib_MerkleTrie.verifyInclusionProof(key, _value, _proof, _root);
    }

    /**
     * @notice Updates a Merkle trie and returns a new root hash.
     * @param _key Key of the node to update, as a hex string.
     * @param _value Value of the node to update, as a hex string.
     * @param _proof Merkle trie inclusion proof for the node *nearest* the
     * target node. If the key exists, we can simply update the value.
     * Otherwise, we need to modify the trie to handle the new k/v pair.
     * @param _root Known root of the Merkle trie. Used to verify that the
     * included proof is correctly constructed.
     * @return _updatedRoot Root hash of the newly constructed trie.
     */
    function update(
        bytes memory _key,
        bytes memory _value,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bytes32 _updatedRoot) {
        bytes memory key = _getSecureKey(_key);
        return Lib_MerkleTrie.update(key, _value, _proof, _root);
    }

    /**
     * @notice Retrieves the value associated with a given key.
     * @param _key Key to search for, as hex bytes.
     * @param _proof Merkle trie inclusion proof for the key.
     * @param _root Known root of the Merkle trie.
     * @return _exists Whether or not the key exists.
     * @return _value Value of the key if it exists.
     */
    function get(
        bytes memory _key,
        bytes memory _proof,
        bytes32 _root
    ) internal pure returns (bool _exists, bytes memory _value) {
        bytes memory key = _getSecureKey(_key);
        return Lib_MerkleTrie.get(key, _proof, _root);
    }

    /**
     * Computes the root hash for a trie with a single node.
     * @param _key Key for the single node.
     * @param _value Value for the single node.
     * @return _updatedRoot Hash of the trie.
     */
    function getSingleNodeRootHash(bytes memory _key, bytes memory _value)
        internal
        pure
        returns (bytes32 _updatedRoot)
    {
        bytes memory key = _getSecureKey(_key);
        return Lib_MerkleTrie.getSingleNodeRootHash(key, _value);
    }

    /*********************
     * Private Functions *
     *********************/

    /**
     * Computes the secure counterpart to a key.
     * @param _key Key to get a secure key from.
     * @return _secureKey Secure version of the key.
     */
    function _getSecureKey(bytes memory _key) private pure returns (bytes memory _secureKey) {
        return abi.encodePacked(keccak256(_key));
    }
}

// File: contracts/libraries/utils/Lib_Bytes32Utils.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_Byte32Utils
 */
library Lib_Bytes32Utils {
    /**********************
     * Internal Functions *
     **********************/

    /**
     * Converts a bytes32 value to a boolean. Anything non-zero will be converted to "true."
     * @param _in Input bytes32 value.
     * @return Bytes32 as a boolean.
     */
    function toBool(bytes32 _in) internal pure returns (bool) {
        return _in != 0;
    }

    /**
     * Converts a boolean to a bytes32 value.
     * @param _in Input boolean value.
     * @return Boolean as a bytes32.
     */
    function fromBool(bool _in) internal pure returns (bytes32) {
        return bytes32(uint256(_in ? 1 : 0));
    }

    /**
     * Converts a bytes32 value to an address. Takes the *last* 20 bytes.
     * @param _in Input bytes32 value.
     * @return Bytes32 as an address.
     */
    function toAddress(bytes32 _in) internal pure returns (address) {
        return address(uint160(uint256(_in)));
    }

    /**
     * Converts an address to a bytes32.
     * @param _in Input address value.
     * @return Address as a bytes32.
     */
    function fromAddress(address _in) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_in)));
    }
}

// File: contracts/libraries/utils/Lib_BytesUtils.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

/**
 * @title Lib_BytesUtils
 */
library Lib_BytesUtils {
    /**********************
     * Internal Functions *
     **********************/

    function slice(
        bytes memory _bytes,
        uint256 _start,
        uint256 _length
    ) internal pure returns (bytes memory) {
        require(_length + 31 >= _length, "slice_overflow");
        require(_start + _length >= _start, "slice_overflow");
        require(_bytes.length >= _start + _length, "slice_outOfBounds");

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
            case 0 {
                // Get a location of some free memory and store it in tempBytes as
                // Solidity does for memory variables.
                tempBytes := mload(0x40)

                // The first word of the slice result is potentially a partial
                // word read from the original array. To read it, we calculate
                // the length of that partial word and start copying that many
                // bytes into the array. The first word we copy will start with
                // data we don't care about, but the last `lengthmod` bytes will
                // land at the beginning of the contents of the new array. When
                // we're done copying, we overwrite the full first word with
                // the actual length of the slice.
                let lengthmod := and(_length, 31)

                // The multiplication in the next line is necessary
                // because when slicing multiples of 32 bytes (lengthmod == 0)
                // the following copy loop was copying the origin's length
                // and then ending prematurely not copying everything it should.
                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                let end := add(mc, _length)

                for {
                    // The multiplication in the next line has the same exact purpose
                    // as the one above.
                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    mstore(mc, mload(cc))
                }

                mstore(tempBytes, _length)

                //update free-memory pointer
                //allocating the array padded to 32 bytes like the compiler does now
                mstore(0x40, and(add(mc, 31), not(31)))
            }
            //if we want a zero-length slice let's just return a zero-length array
            default {
                tempBytes := mload(0x40)

                //zero out the 32 bytes slice we are about to return
                //we need to do it because Solidity does not garbage collect
                mstore(tempBytes, 0)

                mstore(0x40, add(tempBytes, 0x20))
            }
        }

        return tempBytes;
    }

    function slice(bytes memory _bytes, uint256 _start) internal pure returns (bytes memory) {
        if (_start >= _bytes.length) {
            return bytes("");
        }

        return slice(_bytes, _start, _bytes.length - _start);
    }

    function toBytes32(bytes memory _bytes) internal pure returns (bytes32) {
        if (_bytes.length < 32) {
            bytes32 ret;
            assembly {
                ret := mload(add(_bytes, 32))
            }
            return ret;
        }

        return abi.decode(_bytes, (bytes32)); // will truncate if input length > 32 bytes
    }

    function toUint256(bytes memory _bytes) internal pure returns (uint256) {
        return uint256(toBytes32(_bytes));
    }

    function toNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
        bytes memory nibbles = new bytes(_bytes.length * 2);

        for (uint256 i = 0; i < _bytes.length; i++) {
            nibbles[i * 2] = _bytes[i] >> 4;
            nibbles[i * 2 + 1] = bytes1(uint8(_bytes[i]) % 16);
        }

        return nibbles;
    }

    function fromNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
        bytes memory ret = new bytes(_bytes.length / 2);

        for (uint256 i = 0; i < ret.length; i++) {
            ret[i] = (_bytes[i * 2] << 4) | (_bytes[i * 2 + 1]);
        }

        return ret;
    }

    function equal(bytes memory _bytes, bytes memory _other) internal pure returns (bool) {
        return keccak256(_bytes) == keccak256(_other);
    }
}

// File: contracts/standards/AddressAliasHelper.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2019-2021, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.7;

library AddressAliasHelper {
    uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);

    /// @notice Utility function that converts the address in the L1 that submitted a tx to
    /// the inbox to the msg.sender viewed in the L2
    /// @param l1Address the address in the L1 that triggered the tx to L2
    /// @return l2Address L2 address as viewed in msg.sender
    function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
        unchecked {
            l2Address = address(uint160(l1Address) + offset);
        }
    }

    /// @notice Utility function that converts the msg.sender viewed in the L2 to the
    /// address in the L1 that submitted a tx to the inbox
    /// @param l2Address L2 address as viewed in msg.sender
    /// @return l1Address the address in the L1 that triggered the tx to L2
    function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
        unchecked {
            l1Address = address(uint160(l2Address) - offset);
        }
    }
}