Staged more contracts

packages/contracts/contracts/optimistic-ethereum/OVM/chain/OVM_BaseChain.sol

@@ -6,8 +6,8 @@ pragma experimental ABIEncoderV2;
 import { iOVM_BaseChain } from "../../iOVM/chain/iOVM_BaseChain.sol";
 
 /* Library Imports */
-import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
-import { Lib_MerkleUtils } from "../../../libraries/utils/Lib_MerkleUtils.sol";
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+import { Lib_MerkleUtils } from "../../libraries/utils/Lib_MerkleUtils.sol";
 
 /**
  * @title OVM_BaseChain
@@ -27,6 +27,10 @@ contract OVM_BaseChain is iOVM_BaseChain {
      * Public Functions: Batch Retrieval *
      *************************************/
 
+    /**
+     * Gets the total number of submitted elements.
+     * @return _totalElements Total submitted elements.
+     */
     function getTotalElements()
         override
         public
@@ -38,6 +42,10 @@ contract OVM_BaseChain is iOVM_BaseChain {
         return totalElements;
     }
 
+    /**
+     * Gets the total number of submitted batches.
+     * @return _totalBatches Total submitted batches.
+     */
     function getTotalBatches()
         override
         public
@@ -54,10 +62,17 @@ contract OVM_BaseChain is iOVM_BaseChain {
      * Public Functions: Batch Verification *
      ****************************************/
 
+    /**
+     * Verifies an inclusion proof for a given element.
+     * @param _element Element to verify.
+     * @param _batchHeader Header of the batch in which this element was included.
+     * @param _proof Inclusion proof for the element.
+     * @return _verified Whether or not the element was included in the batch.
+     */
     function verifyElement(
         bytes calldata _element,
-        Lib_OVMDataTypes.OVMChainBatchHeader memory _batchHeader,
-        Lib_OVMDataTypes.OVMChainInclusionProof memory _proof
+        Lib_OVMCodec.ChainBatchHeader memory _batchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _proof
     )
         override
         public
@@ -72,7 +87,7 @@ contract OVM_BaseChain is iOVM_BaseChain {
         );
 
         require(
-            libMerkleUtils.verify(
+            Lib_MerkleUtils.verify(
                 _batchHeader.batchRoot,
                 _element,
                 _proof.index,
@@ -89,8 +104,12 @@ contract OVM_BaseChain is iOVM_BaseChain {
      * Internal Functions: Batch Modification *
      ******************************************/
 
+    /**
+     * Appends a batch to the chain.
+     * @param _batchHeader Batch header to append.
+     */
     function _appendBatch(
-        Lib_OVMDataTypes.OVMChainBatchHeader memory _batchHeader
+        Lib_OVMCodec.ChainBatchHeader memory _batchHeader
     )
         internal
     {
@@ -100,36 +119,49 @@ contract OVM_BaseChain is iOVM_BaseChain {
         totalElements += _batchHeader.batchSize;
     }
 
+    /**
+     * Appends a batch to the chain.
+     * @param _elements Elements within the batch.
+     * @param _extraData Any extra data to append to the batch.
+     */
     function _appendBatch(
         bytes[] memory _elements,
         bytes memory _extraData
     )
         internal
     {
-        Lib_OVMDataTypes.OVMChainBatchHeader memory batchHeader = Lib_OVMDataTypes.OVMChainBatchHeader({
+        Lib_OVMCodec.ChainBatchHeader memory batchHeader = Lib_OVMCodec.ChainBatchHeader({
             batchIndex: batches.length,
-            batchRoot: libMerkleUtils.getMerkleRoot(_elements),
+            batchRoot: Lib_MerkleUtils.getMerkleRoot(_elements),
             batchSize: _elements.length,
             prevTotalElements: totalElements,
             extraData: _extraData
         });
 
-        appendBatch(batchHeader);
+        _appendBatch(batchHeader);
     }
 
+    /**
+     * Appends a batch to the chain.
+     * @param _elements Elements within the batch.
+     */
     function _appendBatch(
         bytes[] memory _elements
     )
         internal
     {
-        appendBatch(
+        _appendBatch(
             _elements,
             bytes('')
         );
     }
 
+    /**
+     * Removes a batch from the chain.
+     * @param _batchHeader Header of the batch to remove.
+     */
     function _deleteBatch(
-        Lib_OVMDataTypes.OVMChainBatchHeader memory _batchHeader
+        Lib_OVMCodec.ChainBatchHeader memory _batchHeader
     )
         internal
     {
@@ -152,10 +184,16 @@ contract OVM_BaseChain is iOVM_BaseChain {
      * Private Functions *
      *********************/
 
+    /**
+     * Calculates a hash for a given batch header.
+     * @param _batchHeader Header to hash.
+     * @return _hash Hash of the header.
+     */
     function _hashBatchHeader(
-        Lib_OVMDataTypes.OVMChainBatchHeader memory _batchHeader
+        Lib_OVMCodec.ChainBatchHeader memory _batchHeader
     )
-        internal
+        private
+        pure
         returns (
             bytes32 _hash
         )

packages/contracts/contracts/optimistic-ethereum/OVM/chain/OVM_CanonicalTransactionChain.sol

@@ -3,42 +3,64 @@ pragma solidity ^0.7.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */
-import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
-import { Lib_MerkleUtils } from "../../../libraries/utils/Lib_MerkleUtils.sol";
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+import { Lib_MerkleUtils } from "../../libraries/utils/Lib_MerkleUtils.sol";
 
 /* Interface Imports */
 import { iOVM_CanonicalTransactionChain } from "../../iOVM/chain/iOVM_CanonicalTransactionChain.sol";
-import { iOVM_BaseQueue } from "../../iOVM/queue/iOVM_BaseQueue.sol";
+import { iOVM_L1ToL2TransactionQueue } from "../../iOVM/queue/iOVM_L1ToL2TransactionQueue.sol";
 
 /* Contract Imports */
 import { OVM_BaseChain } from "./OVM_BaseChain.sol";
 
+/**
+ * @title OVM_CanonicalTransactionChain
+ */
 contract OVM_CanonicalTransactionChain is iOVM_CanonicalTransactionChain, OVM_BaseChain {
-    iOVM_BaseQueue internal ovmL1ToL2TransactionQueue;
+
+    /*******************************************
+     * Contract Variables: Contract References *
+     *******************************************/
+    
+    iOVM_L1ToL2TransactionQueue internal ovmL1ToL2TransactionQueue;
     address internal sequencer;
+
+
+    /*******************************************
+     * Contract Variables: Internal Accounting *
+     *******************************************/
+
     uint256 internal forceInclusionPeriodSeconds;
     uint256 internal lastOVMTimestamp;
 
+
+    /***************
+     * Constructor *
+     ***************/
+
+    /**
+     * @param _ovmL1ToL2TransactionQueue Address of the OVM_L1ToL2TransactionQueue.
+     * @param _sequencer Address of the current sequencer.
+     * @param _forceInclusionPeriodSeconds Period during which only the sequencer can submit.
+     */
     constructor(
         address _ovmL1ToL2TransactionQueue,
         address _sequencer,
-        uint256 _forceInclusionPeriodSeconds,
-    )
-        Lib_ContractProxyResolver(_libContractProxyManager)
-    {
-        ovmL1ToL2TransactionQueue = iOVM_BaseQueue(_ovmL1ToL2TransactionQueue);
+        uint256 _forceInclusionPeriodSeconds
+    ) {
+        ovmL1ToL2TransactionQueue = iOVM_L1ToL2TransactionQueue(_ovmL1ToL2TransactionQueue);
         sequencer = _sequencer;
         forceInclusionPeriodSeconds = _forceInclusionPeriodSeconds;
     }
 
-    modifier onlySequencer() {
-        require(
-            msg.sender == sequencer,
-            "Function can only be called by the sequencer."
-        );
-        _;
-    }
 
+    /****************************************
+     * Public Functions: Batch Manipulation *
+     ****************************************/
+
+    /**
+     * Appends a batch from the L1ToL2TransactionQueue.
+     */
     function appendQueueBatch()
         override
         public
@@ -59,14 +81,23 @@ contract OVM_CanonicalTransactionChain is iOVM_CanonicalTransactionChain, OVM_Ba
         ovmL1ToL2TransactionQueue.dequeue();
     }
 
+    /**
+     * Appends a sequencer batch.
+     * @param _batch Batch of transactions to append.
+     * @param _timestamp Timestamp for the provided batch.
+     */
     function appendSequencerBatch(
         bytes[] memory _batch,
         uint256 _timestamp
     )
         override
         public
-        onlySequencer
     {
+        require(
+            msg.sender == sequencer,
+            "Function can only be called by the sequencer."
+        );
+
         require(
             _timestamp >= lastOVMTimestamp,
             "Batch timestamp must be later than the last OVM timestamp."
@@ -87,6 +118,16 @@ contract OVM_CanonicalTransactionChain is iOVM_CanonicalTransactionChain, OVM_Ba
         _appendQueueBatch(queueElement, _batch.length);
     }
 
+
+    /******************************************
+     * Internal Functions: Batch Manipulation *
+     ******************************************/
+
+    /**
+     * Appends a queue batch to the chain.
+     * @param _queueElement Queue element to append.
+     * @param _batchSize Number of elements in the batch.
+     */
     function _appendQueueBatch(
         Lib_OVMCodec.QueueElement memory _queueElement,
         uint256 _batchSize

packages/contracts/contracts/optimistic-ethereum/OVM/chain/OVM_StateCommitmentChain.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.7.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */
-import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
 
 /* Interface Imports */
 import { iOVM_StateCommitmentChain } from "../../iOVM/chain/iOVM_StateCommitmentChain.sol";
@@ -13,20 +13,44 @@ import { iOVM_FraudVerifier } from "../../iOVM/execution/iOVM_FraudVerifier.sol"
 /* Contract Imports */
 import { OVM_BaseChain } from "./OVM_BaseChain.sol";
 
+/**
+ * @title OVM_StateCommitmentChain
+ */
 contract OVM_StateCommitmentChain is iOVM_StateCommitmentChain, OVM_BaseChain {
+    
+    /*******************************************
+     * Contract Variables: Contract References *
+     *******************************************/
+
     iOVM_CanonicalTransactionChain internal ovmCanonicalTransactionChain;
     iOVM_FraudVerifier internal ovmFraudVerifier;
 
+
+    /***************
+     * Constructor *
+     ***************/
+
+    /**
+     * @param _ovmCanonicalTransactionChain Address of the OVM_CanonicalTransactionChain.
+     * @param _ovmFraudVerifier Address of the OVM_FraudVerifier.
+     */
     constructor(
         address _ovmCanonicalTransactionChain,
         address _ovmFraudVerifier
-    )
-        Lib_ContractProxyResolver(_libContractProxyManager)
-    {
+    ) {
         ovmCanonicalTransactionChain = iOVM_CanonicalTransactionChain(_ovmCanonicalTransactionChain);
         ovmFraudVerifier = iOVM_FraudVerifier(_ovmFraudVerifier);
     }
 
+
+    /****************************************
+     * Public Functions: Batch Manipulation *
+     ****************************************/
+
+    /**
+     * Appends a batch of state roots to the chain.
+     * @param _batch Batch of state roots.
+     */
     function appendStateBatch(
         bytes32[] memory _batch
     )
@@ -51,8 +75,12 @@ contract OVM_StateCommitmentChain is iOVM_StateCommitmentChain, OVM_BaseChain {
         _appendBatch(elements);
     }
 
+    /**
+     * Deletes all state roots after (and including) a given batch.
+     * @param _batchHeader Header of the batch to start deleting from.
+     */
     function deleteStateBatch(
-        Lib_OVMDataTypes.OVMChainBatchHeader memory _batchHeader
+        Lib_OVMCodec.ChainBatchHeader memory _batchHeader
     )
         override
         public

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol

@@ -909,7 +909,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         )
     {
         _checkAccountLoad(_address);
-        ovmStateManager.getAccountEthAddress(_address);
+        return ovmStateManager.getAccountEthAddress(_address);
     }
 
     /**

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_FraudVerifier.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
+
+/* Interface Imports */
+import { iOVM_FraudVerifier } from "../../iOVM/execution/iOVM_FraudVerifier.sol";
+import { iOVM_ExecutionManager } from "../../iOVM/execution/iOVM_ExecutionManager.sol";
+import { iOVM_StateTransitioner } from "../../iOVM/execution/iOVM_StateTransitioner.sol";
+import { iOVM_StateTransitionerFactory } from "../../iOVM/execution/iOVM_StateTransitionerFactory.sol";
+import { iOVM_StateManagerFactory } from "../../iOVM/execution/iOVM_StateManagerFactory.sol";
+import { iOVM_StateCommitmentChain } from "../../iOVM/chain/iOVM_StateCommitmentChain.sol";
+import { iOVM_CanonicalTransactionChain } from "../../iOVM/chain/iOVM_CanonicalTransactionChain.sol";
+
+contract OVM_FraudVerifier is iOVM_FraudVerifier {
+
+    /*******************************************
+     * Contract Variables: Contract References *
+     *******************************************/
+
+    iOVM_StateCommitmentChain internal ovmStateCommitmentChain;
+    iOVM_CanonicalTransactionChain internal ovmCanonicalTransactionChain;
+    iOVM_ExecutionManager internal ovmExecutionManager;
+    iOVM_StateManagerFactory internal ovmStateManagerFactory;
+
+    
+    /*******************************************
+     * Contract Variables: Internal Accounting *
+     *******************************************/
+
+    mapping (bytes32 => iOVM_StateTransitioner) internal transitioners;
+    
+
+    /***************
+     * Constructor *
+     ***************/
+
+    /**
+     * @param _ovmStateCommitmentChain Address of the OVM_StateCommitmentChain.
+     * @param _ovmCanonicalTransactionChain Address of the OVM_CanonicalTransactionChain.
+     * @param _ovmExecutionManager Address of the OVM_ExecutionManager.
+     * @param _ovmStateManagerFactory Address of the OVM_StateManagerFactory.
+     */
+    constructor(
+        address _ovmStateCommitmentChain,
+        address _ovmCanonicalTransactionChain,
+        address _ovmExecutionManager,
+        address _ovmStateManagerFactory,
+    ) {
+        ovmStateCommitmentChain = iOVM_StateCommitmentChain(_ovmStateCommitmentChain);
+        ovmCanonicalTransactionChain = iOVM_CanonicalTransactionChain(_ovmCanonicalTransactionChain);
+        ovmExecutionManager = iOVM_ExecutionManager(_ovmExecutionManager);
+        ovmStateManagerFactory = iOVM_StateManagerFactory(_ovmStateManagerFactory);
+    }
+
+
+    /****************************************
+     * Public Functions: Fraud Verification *
+     ****************************************/
+
+    /**
+     * Begins the fraud verification process.
+     * @param _preStateRoot State root before the fraudulent transaction.
+     * @param _preStateRootBatchHeader Batch header for the provided pre-state root.
+     * @param _preStateRootProof Inclusion proof for the provided pre-state root.
+     * @param _transaction OVM transaction claimed to be fraudulent.
+     * @param _transactionBatchHeader Batch header for the provided transaction.
+     * @param _transactionProof Inclusion proof for the provided transaction.
+     */
+    function initializeFraudVerification(
+        bytes32 _preStateRoot,
+        Lib_OVMCodec.ChainBatchHeader memory _preStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _preStateRootProof,
+        Lib_OVMCodec.TransactionData memory _transaction,
+        Lib_OVMCodec.ChainBatchHeader memory _transactionBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _transactionProof
+    )
+        override
+        public
+    {
+        if (_hasStateTransitioner(_preStateRoot)) {
+            return;
+        }
+
+        require(
+            _verifyStateRoot(
+                _preStateRoot,
+                _preStateRootBatchHeader,
+                _preStateRootProof
+            ),
+            "Invalid pre-state root inclusion proof."
+        );
+
+        require(
+            _verifyTransaction(
+                _transaction,
+                _transactionBatchHeader,
+                _transactionProof
+            ),
+            "Invalid transaction inclusion proof."
+        );
+
+        transitioners[_preStateRoot] = iOVM_StateTransitionerFactory(
+            resolve("OVM_StateTransitionerFactory")
+        ).create(
+            address(libContractProxyManager),
+            _preStateRootProof.index,
+            _preStateRoot,
+            Lib_OVMCodec.hash(_transaction)
+        );
+    }
+
+    /**
+     * Finalizes the fraud verification process.
+     * @param _preStateRoot State root before the fraudulent transaction.
+     * @param _preStateRootBatchHeader Batch header for the provided pre-state root.
+     * @param _preStateRootProof Inclusion proof for the provided pre-state root.
+     * @param _postStateRoot State root after the fraudulent transaction.
+     * @param _postStateRootBatchHeader Batch header for the provided post-state root.
+     * @param _postStateRootProof Inclusion proof for the provided post-state root.
+     */
+    function finalizeFraudVerification(
+        bytes32 _preStateRoot,
+        Lib_OVMCodec.ChainBatchHeader memory _preStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _preStateRootProof,
+        bytes32 _postStateRoot,
+        Lib_OVMCodec.ChainBatchHeader memory _postStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _postStateRootProof
+    )
+        override
+        public
+    {
+        iOVM_StateTransitioner transitioner = transitioners[_preStateRoot];
+
+        require(
+            transitioner.isComplete() == true,
+            "State transition process must be completed prior to finalization."
+        );
+
+        require(
+            _postStateRootProof.index == _preStateRootProof.index + 1,
+            "Invalid post-state root index."
+        );
+
+        require(
+            _verifyStateRoot(
+                _preStateRoot,
+                _preStateRootBatchHeader,
+                _preStateRootProof
+            ),
+            "Invalid pre-state root inclusion proof."
+        );
+
+        require(
+            _verifyStateRoot(
+                _postStateRoot,
+                _postStateRootBatchHeader,
+                _postStateRootProof
+            ),
+            "Invalid post-state root inclusion proof."
+        );
+
+        require(
+            _postStateRoot != transitioner.postStateRoot(),
+            "State transition has not been proven fraudulent."
+        );
+
+        ovmStateCommitmentChain.deleteStateBatch(
+            _postStateRootBatchHeader
+        );
+    }
+
+
+    /************************************
+     * Internal Functions: Verification *
+     ************************************/
+
+    /**
+     * Checks whether a transitioner already exists for a given pre-state root.
+     * @param _preStateRoot Pre-state root to check.
+     * @return _exists Whether or not we already have a transitioner for the root.
+     */
+    function _hasStateTransitioner(
+        bytes32 _preStateRoot
+    )
+        internal
+        view
+        returns (
+            bool _exists
+        )
+    {
+        return address(transitioners[_preStateRoot]) != address(0);
+    }
+
+    /**
+     * Verifies inclusion of a state root.
+     * @param _stateRoot State root to verify
+     * @param _stateRootBatchHeader Batch header for the provided state root.
+     * @param _stateRootProof Inclusion proof for the provided state root.
+     * @return _verified Whether or not the root was included.
+     */
+    function _verifyStateRoot(
+        bytes32 _stateRoot,
+        Lib_OVMCodec.ChainBatchHeader memory _stateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _stateRootProof
+    )
+        internal
+        view
+        returns (
+            bool _verified
+        )
+    {
+        return ovmStateCommitmentChain.ovmBaseChain().verifyElement(
+            abi.encodePacked(_stateRoot),
+            _stateRootBatchHeader,
+            _stateRootProof
+        );
+    }
+
+    /**
+     * Verifies inclusion of a given transaction.
+     * @param _transaction OVM transaction to verify.
+     * @param _transactionBatchHeader Batch header for the provided transaction.
+     * @param _transactionProof Inclusion proof for the provided transaction.
+     * @return _verified Whether or not the transaction was included.
+     */
+    function _verifyTransaction(
+        Lib_OVMCodec.TransactionData memory _transaction,
+        Lib_OVMCodec.ChainBatchHeader memory _transactionBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof memory _transactionProof
+    )
+        internal
+        view
+        returns (
+            bool _verified
+        )
+    {
+        return ovmCanonicalTransactionChain.ovmBaseChain().verifyElement(
+            Lib_OVMCodec.encode(_transaction),
+            _transactionBatchHeader,
+            _transactionProof
+        );
+    }
+}

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_StateManagerFactory.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+
+/* Interface Imports */
+import { iOVM_StateManager } from "../../iOVM/execution/iOVM_StateManager.sol";
+import { iOVM_StateManagerFactory } from "../../iOVM/execution/iOVM_StateManagerFactory.sol";
+
+/* Contract Imports */
+import { OVM_StateManager } from "./OVM_StateManager.sol";
+
+/**
+ * @title OVM_StateManagerFactory
+ */
+contract OVM_StateManagerFactory is iOVM_StateManagerFactory {
+
+    /***************************************
+     * Public Functions: Contract Creation *
+     ***************************************/
+
+    function create()
+        override
+        public
+        returns (
+            iOVM_StateManager _ovmStateManager
+        )
+    {
+        return new OVM_StateManager();
+    }
+}

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_StateTransitionerFactory.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+
+/* Interface Imports */
+import { iOVM_StateTransitioner } from "../../iOVM/execution/iOVM_StateTransitioner.sol";
+import { iOVM_StateTransitionerFactory } from "../../iOVM/execution/iOVM_StateTransitionerFactory.sol";
+
+/* Contract Imports */
+import { OVM_StateTransitioner } from "./OVM_StateTransitioner.sol";
+
+/**
+ * @title OVM_StateTransitionerFactory
+ */
+contract OVM_StateTransitionerFactory is iOVM_StateTransitionerFactory {
+
+    /***************************************
+     * Public Functions: Contract Creation *
+     ***************************************/
+
+    function create(
+        address _libContractProxyManager,
+        uint256 _stateTransitionIndex,
+        bytes32 _preStateRoot,
+        bytes32 _transactionHash
+    )
+        override
+        public
+        returns (
+            iOVM_StateTransitioner _ovmStateTransitioner
+        )
+    {
+        return new OVM_StateTransitioner(
+            _libContractProxyManager,
+            _stateTransitionIndex,
+            _preStateRoot,
+            _transactionHash
+        );
+    }
+}

packages/contracts/contracts/optimistic-ethereum/OVM/queue/OVM_BaseQueue.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+
+/* Interface Imports */
+import { iOVM_BaseQueue } from "../../iOVM/queue/iOVM_BaseQueue.sol";
+
+/**
+ * @title OVM_BaseQueue
+ */
+contract OVM_BaseQueue is iOVM_BaseQueue {
+
+    /****************************************
+     * Contract Variables: Internal Storage *
+     ****************************************/
+
+    Lib_OVMCodec.QueueElement[] internal queue;
+    uint256 internal front;
+
+
+    /**********************
+     * Function Modifiers *
+     **********************/
+
+    /**
+     * Asserts that the queue is not empty.
+     */
+    modifier notEmpty() {
+        require(
+            size() > 0,
+            "Queue is empty."
+        );
+        _;
+    }
+
+
+    /**********************************
+     * Public Functions: Queue Access *
+     **********************************/
+
+    /**
+     * Gets the size of the queue.
+     * @return _size Number of elements in the queue.
+     */
+    function size()
+        override
+        public
+        view
+        returns (
+            uint256 _size
+        )
+    {
+        return front >= queue.length ? 0 : queue.length - front;
+    }
+
+    /**
+     * Gets the top element of the queue.
+     * @return _element First element in the queue.
+     */
+    function peek()
+        override
+        public
+        view
+        notEmpty
+        returns (
+            Lib_OVMCodec.QueueElement memory _element
+        )
+    {
+        return queue[front];
+    }
+
+
+    /******************************************
+     * Internal Functions: Queue Manipulation *
+     ******************************************/
+
+    /**
+     * Adds an element to the queue.
+     * @param _element Queue element to add to the queue.
+     */
+    function _enqueue(
+        Lib_OVMCodec.QueueElement memory _element
+    )
+        internal
+    {
+        queue.push(_element);
+    }
+
+    /**
+     * Pops an element from the queue.
+     * @return _element Queue element popped from the queue.
+     */
+    function _dequeue()
+        internal
+        notEmpty
+        returns (
+            Lib_OVMCodec.QueueElement memory _element
+        )
+    {
+        _element = queue[front];
+        delete queue[front];
+        front += 1;
+        return _element;
+    }
+}

packages/contracts/contracts/optimistic-ethereum/OVM/queue/OVM_L1ToL2TransactionQueue.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+
+/* Interface Imports */
+import { iOVM_L1ToL2TransactionQueue } from "../../iOVM/queue/iOVM_L1ToL2TransactionQueue.sol";
+import { iOVM_CanonicalTransactionChain } from "../../iOVM/chain/iOVM_CanonicalTransactionChain.sol";
+
+/* Contract Imports */
+import { OVM_BaseQueue } from "./OVM_BaseQueue.sol";
+
+/**
+ * @title OVM_L1ToL2TransactionQueue
+ */
+contract OVM_L1ToL2TransactionQueue is iOVM_L1ToL2TransactionQueue, OVM_BaseQueue {
+
+    /*******************************************
+     * Contract Variables: Contract References *
+     *******************************************/
+
+    iOVM_CanonicalTransactionChain internal ovmCanonicalTransactionChain;
+
+
+    /***************
+     * Constructor *
+     ***************/
+
+    /**
+     * @param _ovmCanonicalTransactionChain Address of the OVM_CanonicalTransactionChain.
+     */
+    constructor(
+        address _ovmCanonicalTransactionChain
+    ) {
+        ovmCanonicalTransactionChain = iOVM_CanonicalTransactionChain(_ovmCanonicalTransactionChain);
+    }
+
+
+    /****************************************
+     * Public Functions: Queue Manipulation *
+     ****************************************/
+
+    /**
+     * Adds an element to the queue.
+     * @param _element Queue element to add to the queue.
+     */
+    function enqueue(
+        Lib_OVMCodec.QueueElement memory _element
+    )
+        override
+        public
+    {
+        _enqueue(_element);
+    }
+
+    /**
+     * Pops an element from the queue.
+     * @return _element Queue element popped from the queue.
+     */
+    function dequeue()
+        override
+        public
+        returns (
+            Lib_OVMCodec.QueueElement memory _element
+        )
+    {
+        require(
+            msg.sender == address(ovmCanonicalTransactionChain),
+            "Sender is not allowed to enqueue."
+        );
+
+        return _dequeue();
+    }
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/chain/iOVM_BaseChain.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.7.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */
-import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
 
 /**
  * @title iOVM_BaseChain

packages/contracts/contracts/optimistic-ethereum/iOVM/chain/iOVM_CanonicalTransactionChain.sol

@@ -5,7 +5,15 @@ pragma experimental ABIEncoderV2;
 /* Interface Imports */
 import { iOVM_BaseChain } from "./iOVM_BaseChain.sol";
 
+/**
+ * @title iOVM_CanonicalTransactionChain
+ */
 interface iOVM_CanonicalTransactionChain is iOVM_BaseChain {
+
+    /****************************************
+     * Public Functions: Batch Manipulation *
+     ****************************************/
+
     function appendQueueBatch() external;
     function appendSequencerBatch(bytes[] calldata _batch, uint256 _timestamp) external;
 }

packages/contracts/contracts/optimistic-ethereum/iOVM/chain/iOVM_StateCommitmentChain.sol

@@ -6,9 +6,17 @@ pragma experimental ABIEncoderV2;
 import { iOVM_BaseChain } from "./iOVM_BaseChain.sol";
 
 /* Library Imports */
-import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
 
+/**
+ * @title iOVM_StateCommitmentChain
+ */
 interface iOVM_StateCommitmentChain is iOVM_BaseChain {
+
+    /****************************************
+     * Public Functions: Batch Manipulation *
+     ****************************************/
+
     function appendStateBatch(bytes32[] calldata _batch) external;
     function deleteStateBatch(Lib_OVMCodec.ChainBatchHeader memory _batchHeader) external;
 }

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_FraudVerifier.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+
+/**
+ * @title iOVM_FraudVerifier
+ */
+interface iOVM_FraudVerifier {
+
+    /****************************************
+     * Public Functions: Fraud Verification *
+     ****************************************/
+
+    function initializeFraudVerification(
+        bytes32 _preStateRoot,
+        Lib_OVMCodec.ChainBatchHeader calldata _preStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof calldata _preStateRootProof,
+        Lib_OVMCodec.Transaction calldata _transaction,
+        Lib_OVMCodec.ChainBatchHeader calldata _transactionBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof calldata _transactionProof
+    ) external;
+
+    function finalizeFraudVerification(
+        bytes32 _preStateRoot,
+        Lib_OVMCodec.ChainBatchHeader calldata _preStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof calldata _preStateRootProof,
+        bytes32 _postStateRoot,
+        Lib_OVMCodec.ChainBatchHeader calldata _postStateRootBatchHeader,
+        Lib_OVMCodec.ChainInclusionProof calldata _postStateRootProof
+    ) external;
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_StateManagerFactory.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+
+/* Contract Imports */
+import { iOVM_StateManager } from "./iOVM_StateManager.sol";
+
+/**
+ * @title iOVM_StateManagerFactory
+ */
+interface iOVM_StateManagerFactory {
+
+    /***************************************
+     * Public Functions: Contract Creation *
+     ***************************************/
+
+    function create()
+        external
+        returns (
+            iOVM_StateManager _ovmStateManager
+        );
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_StateTransitioner.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../../libraries/codec/Lib_OVMCodec.sol";
+
+/**
+ * @title iOVM_StateTransitioner
+ */
+interface iOVM_StateTransitioner {
+
+    /**********************************
+     * Public Functions: State Access *
+     **********************************/
+
+    function getPreStateRoot() external view returns (bytes32 _preStateRoot);
+    function getPostStateRoot() external view returns (bytes32 _postStateRoot);
+    function isComplete() external view returns (bool _complete);
+
+    
+    /***********************************
+     * Public Functions: Pre-Execution *
+     ***********************************/
+
+    function proveContractState(
+        address _ovmContractAddress,
+        Lib_OVMCodec.Account calldata _account,
+        bytes calldata _stateTrieWitness
+    ) external;
+
+    function proveStorageSlot(
+        address _ovmContractAddress,
+        bytes32 _key,
+        bytes32 _value,
+        bytes calldata _stateTrieWitness,
+        bytes calldata _storageTrieWitness
+    ) external;
+
+
+    /*******************************
+     * Public Functions: Execution *
+     *******************************/
+
+    function applyTransaction(
+        Lib_OVMCodec.TransactionData calldata _transaction
+    ) external;
+
+
+    /************************************
+     * Public Functions: Post-Execution *
+     ************************************/
+
+    function commitContractState(
+        address _ovmContractAddress,
+        Lib_OVMCodec.Account calldata _account,
+        bytes calldata _stateTrieWitness
+    ) external;
+
+    function commitStorageSlot(
+        address _ovmContractAddress,
+        bytes32 _key,
+        bytes32 _value,
+        bytes calldata _stateTrieWitness,
+        bytes calldata _storageTrieWitness
+    ) external;
+
+
+    /**********************************
+     * Public Functions: Finalization *
+     **********************************/
+
+    function completeTransition() external;
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_StateTransitionerFactory.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+
+/* Contract Imports */
+import { iOVM_StateTransitioner } from "./iOVM_StateTransitioner.sol";
+
+/**
+ * @title iOVM_StateTransitionerFactory
+ */
+interface iOVM_StateTransitionerFactory {
+
+    /***************************************
+     * Public Functions: Contract Creation *
+     ***************************************/
+
+    function create(
+        address _libContractProxyManager,
+        uint256 _stateTransitionIndex,
+        bytes32 _preStateRoot,
+        bytes32 _transactionHash
+    )
+        external
+        returns (
+            iOVM_StateTransitioner _ovmStateTransitioner
+        );
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/queue/iOVM_BaseQueue.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+
+/**
+ * @title iOVM_BaseQueue
+ */
+interface iOVM_BaseQueue {
+
+    /**********************************
+     * Public Functions: Queue Access *
+     **********************************/
+
+    function size() external view returns (uint256 _size);
+    function peek() external view returns (Lib_OVMCodec.QueueElement memory _element);
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/queue/iOVM_L1ToL2TransactionQueue.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* Library Imports */
+import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
+
+/* Interface Imports */
+import { iOVM_BaseQueue } from "./iOVM_BaseQueue.sol";
+
+/**
+ * @title iOVM_L1ToL2TransactionQueue
+ */
+interface iOVM_L1ToL2TransactionQueue is iOVM_BaseQueue {
+
+    /****************************************
+     * Public Functions: Queue Manipulation *
+     ****************************************/
+
+    function enqueue(Lib_OVMCodec.QueueElement memory _element) external;
+    function dequeue() external returns (Lib_OVMCodec.QueueElement memory _element);
+}

packages/contracts/contracts/optimistic-ethereum/iOVM/trie/Lib_SecureMerkleTrie.sol

+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
+
+/* 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 `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
+    )
+        public
+        view
+        returns (bool)
+    {
+        bytes memory key = _getSecureKey(_key);
+        return Lib_MerkleTrie.verifyInclusionProof(key, _value, _proof, _root);
+    }
+
+    /**
+     * @notice Verifies a proof that a given key/value pair is *not* 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 node *nearest* the
+     * target node. We effectively need to show that either the key exists and
+     * its value differs, or the key does not exist at all.
+     * @param _root Known root of the Merkle trie. Used to verify that the
+     * included proof is correctly constructed.
+     * @return `true` if the k/v pair is absent in the trie, `false` otherwise.
+     */
+    function verifyExclusionProof(
+        bytes memory _key,
+        bytes memory _value,
+        bytes memory _proof,
+        bytes32 _root
+    )
+        public
+        view
+        returns (bool)
+    {
+        bytes memory key = _getSecureKey(_key);
+        return Lib_MerkleTrie.verifyExclusionProof(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 Root hash of the newly constructed trie.
+     */
+    function update(
+        bytes memory _key,
+        bytes memory _value,
+        bytes memory _proof,
+        bytes32 _root
+    )
+        public
+        view
+        returns (bytes32)
+    {
+        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 Whether the node exists, value associated with the key if so.
+     */
+    function get(
+        bytes memory _key,
+        bytes memory _proof,
+        bytes32 _root
+    )
+        public
+        view
+        returns (bool, bytes memory)
+    {
+        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 Hash of the trie.
+     */
+    function getSingleNodeRootHash(
+        bytes memory _key,
+        bytes memory _value
+    )
+        public
+        view
+        returns (bytes32)
+    {
+        bytes memory key = _getSecureKey(_key);
+        return Lib_MerkleTrie.getSingleNodeRootHash(key, _value);
+    }
+
+
+    /*********************
+     * Private Functions *
+     *********************/
+
+    function _getSecureKey(
+        bytes memory _key
+    ) private pure returns (bytes memory) {
+        return abi.encodePacked(keccak256(_key));
+    }
+}
\ No newline at end of file

packages/contracts/contracts/optimistic-ethereum/libraries/codec/Lib_OVMCodec.sol

@@ -22,6 +22,13 @@ library Lib_OVMCodec {
         address ethAddress;
     }
 
+    struct EVMAccount {
+        uint256 nonce;
+        uint256 balance;
+        bytes32 storageRoot;
+        bytes32 codeHash;
+    }
+
     struct ChainBatchHeader {
         uint256 batchIndex;
         bytes32 batchRoot;