ETH Price: $2,255.43 (-1.12%)

Transaction Decoder

Block:
6428080 at Sep-30-2018 03:29:49 PM +UTC
Transaction Fee:
0.000573045 ETH $1.29
Gas Used:
38,203 Gas / 15 Gwei

Emitted Events:

61 TolarToken.Transfer( from=[Sender] 0xca594f490a965648cff2216b027b151c3213f1cc, to=[Receiver] EtherDelta, value=1000000000000000000000 )
62 EtherDelta.Deposit( token=TolarToken, user=[Sender] 0xca594f490a965648cff2216b027b151c3213f1cc, amount=1000000000000000000000, balance=1000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
(DwarfPool)
237.266471876547805567 Eth237.267044921547805567 Eth0.000573045
0x8d12A197...2A5CC6819
(EtherDelta 2)
0xca594F49...c3213f1cC
0.019515211000000001 Eth
Nonce: 350
0.018942166000000001 Eth
Nonce: 351
0.000573045
0xd07D9Fe2...804f42cFA

Execution Trace

EtherDelta.depositToken( token=0xd07D9Fe2d2cc067015E2b4917D24933804f42cFA, amount=1000000000000000000000 )
  • TolarToken.transferFrom( _from=0xca594F490a965648CfF2216b027b151c3213f1cC, _to=0x8d12A197cB00D4747a1fe03395095ce2A5CC6819, _value=1000000000000000000000 ) => ( True )
    File 1 of 2: EtherDelta
    pragma solidity ^0.4.9;
    
    contract SafeMath {
      function safeMul(uint a, uint b) internal returns (uint) {
        uint c = a * b;
        assert(a == 0 || c / a == b);
        return c;
      }
    
      function safeSub(uint a, uint b) internal returns (uint) {
        assert(b <= a);
        return a - b;
      }
    
      function safeAdd(uint a, uint b) internal returns (uint) {
        uint c = a + b;
        assert(c>=a && c>=b);
        return c;
      }
    
      function assert(bool assertion) internal {
        if (!assertion) throw;
      }
    }
    
    contract Token {
      /// @return total amount of tokens
      function totalSupply() constant returns (uint256 supply) {}
    
      /// @param _owner The address from which the balance will be retrieved
      /// @return The balance
      function balanceOf(address _owner) constant returns (uint256 balance) {}
    
      /// @notice send `_value` token to `_to` from `msg.sender`
      /// @param _to The address of the recipient
      /// @param _value The amount of token to be transferred
      /// @return Whether the transfer was successful or not
      function transfer(address _to, uint256 _value) returns (bool success) {}
    
      /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
      /// @param _from The address of the sender
      /// @param _to The address of the recipient
      /// @param _value The amount of token to be transferred
      /// @return Whether the transfer was successful or not
      function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}
    
      /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
      /// @param _spender The address of the account able to transfer the tokens
      /// @param _value The amount of wei to be approved for transfer
      /// @return Whether the approval was successful or not
      function approve(address _spender, uint256 _value) returns (bool success) {}
    
      /// @param _owner The address of the account owning tokens
      /// @param _spender The address of the account able to transfer the tokens
      /// @return Amount of remaining tokens allowed to spent
      function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}
    
      event Transfer(address indexed _from, address indexed _to, uint256 _value);
      event Approval(address indexed _owner, address indexed _spender, uint256 _value);
    
      uint public decimals;
      string public name;
    }
    
    contract StandardToken is Token {
    
      function transfer(address _to, uint256 _value) returns (bool success) {
        //Default assumes totalSupply can't be over max (2^256 - 1).
        //If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
        //Replace the if with this one instead.
        if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
        //if (balances[msg.sender] >= _value && _value > 0) {
          balances[msg.sender] -= _value;
          balances[_to] += _value;
          Transfer(msg.sender, _to, _value);
          return true;
        } else { return false; }
      }
    
      function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        //same as above. Replace this line with the following if you want to protect against wrapping uints.
        if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
        //if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
          balances[_to] += _value;
          balances[_from] -= _value;
          allowed[_from][msg.sender] -= _value;
          Transfer(_from, _to, _value);
          return true;
        } else { return false; }
      }
    
      function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
      }
    
      function approve(address _spender, uint256 _value) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
      }
    
      function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
      }
    
      mapping(address => uint256) balances;
    
      mapping (address => mapping (address => uint256)) allowed;
    
      uint256 public totalSupply;
    }
    
    contract ReserveToken is StandardToken, SafeMath {
      address public minter;
      function ReserveToken() {
        minter = msg.sender;
      }
      function create(address account, uint amount) {
        if (msg.sender != minter) throw;
        balances[account] = safeAdd(balances[account], amount);
        totalSupply = safeAdd(totalSupply, amount);
      }
      function destroy(address account, uint amount) {
        if (msg.sender != minter) throw;
        if (balances[account] < amount) throw;
        balances[account] = safeSub(balances[account], amount);
        totalSupply = safeSub(totalSupply, amount);
      }
    }
    
    contract AccountLevels {
      //given a user, returns an account level
      //0 = regular user (pays take fee and make fee)
      //1 = market maker silver (pays take fee, no make fee, gets rebate)
      //2 = market maker gold (pays take fee, no make fee, gets entire counterparty's take fee as rebate)
      function accountLevel(address user) constant returns(uint) {}
    }
    
    contract AccountLevelsTest is AccountLevels {
      mapping (address => uint) public accountLevels;
    
      function setAccountLevel(address user, uint level) {
        accountLevels[user] = level;
      }
    
      function accountLevel(address user) constant returns(uint) {
        return accountLevels[user];
      }
    }
    
    contract EtherDelta is SafeMath {
      address public admin; //the admin address
      address public feeAccount; //the account that will receive fees
      address public accountLevelsAddr; //the address of the AccountLevels contract
      uint public feeMake; //percentage times (1 ether)
      uint public feeTake; //percentage times (1 ether)
      uint public feeRebate; //percentage times (1 ether)
      mapping (address => mapping (address => uint)) public tokens; //mapping of token addresses to mapping of account balances (token=0 means Ether)
      mapping (address => mapping (bytes32 => bool)) public orders; //mapping of user accounts to mapping of order hashes to booleans (true = submitted by user, equivalent to offchain signature)
      mapping (address => mapping (bytes32 => uint)) public orderFills; //mapping of user accounts to mapping of order hashes to uints (amount of order that has been filled)
    
      event Order(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user);
      event Cancel(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s);
      event Trade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, address get, address give);
      event Deposit(address token, address user, uint amount, uint balance);
      event Withdraw(address token, address user, uint amount, uint balance);
    
      function EtherDelta(address admin_, address feeAccount_, address accountLevelsAddr_, uint feeMake_, uint feeTake_, uint feeRebate_) {
        admin = admin_;
        feeAccount = feeAccount_;
        accountLevelsAddr = accountLevelsAddr_;
        feeMake = feeMake_;
        feeTake = feeTake_;
        feeRebate = feeRebate_;
      }
    
      function() {
        throw;
      }
    
      function changeAdmin(address admin_) {
        if (msg.sender != admin) throw;
        admin = admin_;
      }
    
      function changeAccountLevelsAddr(address accountLevelsAddr_) {
        if (msg.sender != admin) throw;
        accountLevelsAddr = accountLevelsAddr_;
      }
    
      function changeFeeAccount(address feeAccount_) {
        if (msg.sender != admin) throw;
        feeAccount = feeAccount_;
      }
    
      function changeFeeMake(uint feeMake_) {
        if (msg.sender != admin) throw;
        if (feeMake_ > feeMake) throw;
        feeMake = feeMake_;
      }
    
      function changeFeeTake(uint feeTake_) {
        if (msg.sender != admin) throw;
        if (feeTake_ > feeTake || feeTake_ < feeRebate) throw;
        feeTake = feeTake_;
      }
    
      function changeFeeRebate(uint feeRebate_) {
        if (msg.sender != admin) throw;
        if (feeRebate_ < feeRebate || feeRebate_ > feeTake) throw;
        feeRebate = feeRebate_;
      }
    
      function deposit() payable {
        tokens[0][msg.sender] = safeAdd(tokens[0][msg.sender], msg.value);
        Deposit(0, msg.sender, msg.value, tokens[0][msg.sender]);
      }
    
      function withdraw(uint amount) {
        if (tokens[0][msg.sender] < amount) throw;
        tokens[0][msg.sender] = safeSub(tokens[0][msg.sender], amount);
        if (!msg.sender.call.value(amount)()) throw;
        Withdraw(0, msg.sender, amount, tokens[0][msg.sender]);
      }
    
      function depositToken(address token, uint amount) {
        //remember to call Token(address).approve(this, amount) or this contract will not be able to do the transfer on your behalf.
        if (token==0) throw;
        if (!Token(token).transferFrom(msg.sender, this, amount)) throw;
        tokens[token][msg.sender] = safeAdd(tokens[token][msg.sender], amount);
        Deposit(token, msg.sender, amount, tokens[token][msg.sender]);
      }
    
      function withdrawToken(address token, uint amount) {
        if (token==0) throw;
        if (tokens[token][msg.sender] < amount) throw;
        tokens[token][msg.sender] = safeSub(tokens[token][msg.sender], amount);
        if (!Token(token).transfer(msg.sender, amount)) throw;
        Withdraw(token, msg.sender, amount, tokens[token][msg.sender]);
      }
    
      function balanceOf(address token, address user) constant returns (uint) {
        return tokens[token][user];
      }
    
      function order(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce) {
        bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
        orders[msg.sender][hash] = true;
        Order(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, msg.sender);
      }
    
      function trade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s, uint amount) {
        //amount is in amountGet terms
        bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
        if (!(
          (orders[user][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == user) &&
          block.number <= expires &&
          safeAdd(orderFills[user][hash], amount) <= amountGet
        )) throw;
        tradeBalances(tokenGet, amountGet, tokenGive, amountGive, user, amount);
        orderFills[user][hash] = safeAdd(orderFills[user][hash], amount);
        Trade(tokenGet, amount, tokenGive, amountGive * amount / amountGet, user, msg.sender);
      }
    
      function tradeBalances(address tokenGet, uint amountGet, address tokenGive, uint amountGive, address user, uint amount) private {
        uint feeMakeXfer = safeMul(amount, feeMake) / (1 ether);
        uint feeTakeXfer = safeMul(amount, feeTake) / (1 ether);
        uint feeRebateXfer = 0;
        if (accountLevelsAddr != 0x0) {
          uint accountLevel = AccountLevels(accountLevelsAddr).accountLevel(user);
          if (accountLevel==1) feeRebateXfer = safeMul(amount, feeRebate) / (1 ether);
          if (accountLevel==2) feeRebateXfer = feeTakeXfer;
        }
        tokens[tokenGet][msg.sender] = safeSub(tokens[tokenGet][msg.sender], safeAdd(amount, feeTakeXfer));
        tokens[tokenGet][user] = safeAdd(tokens[tokenGet][user], safeSub(safeAdd(amount, feeRebateXfer), feeMakeXfer));
        tokens[tokenGet][feeAccount] = safeAdd(tokens[tokenGet][feeAccount], safeSub(safeAdd(feeMakeXfer, feeTakeXfer), feeRebateXfer));
        tokens[tokenGive][user] = safeSub(tokens[tokenGive][user], safeMul(amountGive, amount) / amountGet);
        tokens[tokenGive][msg.sender] = safeAdd(tokens[tokenGive][msg.sender], safeMul(amountGive, amount) / amountGet);
      }
    
      function testTrade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s, uint amount, address sender) constant returns(bool) {
        if (!(
          tokens[tokenGet][sender] >= amount &&
          availableVolume(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, user, v, r, s) >= amount
        )) return false;
        return true;
      }
    
      function availableVolume(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s) constant returns(uint) {
        bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
        if (!(
          (orders[user][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == user) &&
          block.number <= expires
        )) return 0;
        uint available1 = safeSub(amountGet, orderFills[user][hash]);
        uint available2 = safeMul(tokens[tokenGive][user], amountGet) / amountGive;
        if (available1<available2) return available1;
        return available2;
      }
    
      function amountFilled(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s) constant returns(uint) {
        bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
        return orderFills[user][hash];
      }
    
      function cancelOrder(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, uint8 v, bytes32 r, bytes32 s) {
        bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
        if (!(orders[msg.sender][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == msg.sender)) throw;
        orderFills[msg.sender][hash] = amountGet;
        Cancel(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, msg.sender, v, r, s);
      }
    }

    File 2 of 2: TolarToken
    pragma solidity 0.4.24;
    
    // File: openzeppelin-solidity/contracts/ownership/Ownable.sol
    
    /**
     * @title Ownable
     * @dev The Ownable contract has an owner address, and provides basic authorization control
     * functions, this simplifies the implementation of "user permissions".
     */
    contract Ownable {
      address public owner;
    
    
      event OwnershipRenounced(address indexed previousOwner);
      event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
      );
    
    
      /**
       * @dev The Ownable constructor sets the original `owner` of the contract to the sender
       * account.
       */
      constructor() public {
        owner = msg.sender;
      }
    
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
        require(msg.sender == owner);
        _;
      }
    
      /**
       * @dev Allows the current owner to relinquish control of the contract.
       * @notice Renouncing to ownership will leave the contract without an owner.
       * It will not be possible to call the functions with the `onlyOwner`
       * modifier anymore.
       */
      function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(owner);
        owner = address(0);
      }
    
      /**
       * @dev Allows the current owner to transfer control of the contract to a newOwner.
       * @param _newOwner The address to transfer ownership to.
       */
      function transferOwnership(address _newOwner) public onlyOwner {
        _transferOwnership(_newOwner);
      }
    
      /**
       * @dev Transfers control of the contract to a newOwner.
       * @param _newOwner The address to transfer ownership to.
       */
      function _transferOwnership(address _newOwner) internal {
        require(_newOwner != address(0));
        emit OwnershipTransferred(owner, _newOwner);
        owner = _newOwner;
      }
    }
    
    // File: openzeppelin-solidity/contracts/ownership/HasNoEther.sol
    
    /**
     * @title Contracts that should not own Ether
     * @author Remco Bloemen <remco@2π.com>
     * @dev This tries to block incoming ether to prevent accidental loss of Ether. Should Ether end up
     * in the contract, it will allow the owner to reclaim this Ether.
     * @notice Ether can still be sent to this contract by:
     * calling functions labeled `payable`
     * `selfdestruct(contract_address)`
     * mining directly to the contract address
     */
    contract HasNoEther is Ownable {
    
      /**
      * @dev Constructor that rejects incoming Ether
      * The `payable` flag is added so we can access `msg.value` without compiler warning. If we
      * leave out payable, then Solidity will allow inheriting contracts to implement a payable
      * constructor. By doing it this way we prevent a payable constructor from working. Alternatively
      * we could use assembly to access msg.value.
      */
      constructor() public payable {
        require(msg.value == 0);
      }
    
      /**
       * @dev Disallows direct send by setting a default function without the `payable` flag.
       */
      function() external {
      }
    
      /**
       * @dev Transfer all Ether held by the contract to the owner.
       */
      function reclaimEther() external onlyOwner {
        owner.transfer(address(this).balance);
      }
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/ERC20Basic.sol
    
    /**
     * @title ERC20Basic
     * @dev Simpler version of ERC20 interface
     * See https://github.com/ethereum/EIPs/issues/179
     */
    contract ERC20Basic {
      function totalSupply() public view returns (uint256);
      function balanceOf(address _who) public view returns (uint256);
      function transfer(address _to, uint256 _value) public returns (bool);
      event Transfer(address indexed from, address indexed to, uint256 value);
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/ERC20.sol
    
    /**
     * @title ERC20 interface
     * @dev see https://github.com/ethereum/EIPs/issues/20
     */
    contract ERC20 is ERC20Basic {
      function allowance(address _owner, address _spender)
        public view returns (uint256);
    
      function transferFrom(address _from, address _to, uint256 _value)
        public returns (bool);
    
      function approve(address _spender, uint256 _value) public returns (bool);
      event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
      );
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/SafeERC20.sol
    
    /**
     * @title SafeERC20
     * @dev Wrappers around ERC20 operations that throw on failure.
     * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
     * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
     */
    library SafeERC20 {
      function safeTransfer(
        ERC20Basic _token,
        address _to,
        uint256 _value
      )
        internal
      {
        require(_token.transfer(_to, _value));
      }
    
      function safeTransferFrom(
        ERC20 _token,
        address _from,
        address _to,
        uint256 _value
      )
        internal
      {
        require(_token.transferFrom(_from, _to, _value));
      }
    
      function safeApprove(
        ERC20 _token,
        address _spender,
        uint256 _value
      )
        internal
      {
        require(_token.approve(_spender, _value));
      }
    }
    
    // File: openzeppelin-solidity/contracts/ownership/CanReclaimToken.sol
    
    /**
     * @title Contracts that should be able to recover tokens
     * @author SylTi
     * @dev This allow a contract to recover any ERC20 token received in a contract by transferring the balance to the contract owner.
     * This will prevent any accidental loss of tokens.
     */
    contract CanReclaimToken is Ownable {
      using SafeERC20 for ERC20Basic;
    
      /**
       * @dev Reclaim all ERC20Basic compatible tokens
       * @param _token ERC20Basic The address of the token contract
       */
      function reclaimToken(ERC20Basic _token) external onlyOwner {
        uint256 balance = _token.balanceOf(this);
        _token.safeTransfer(owner, balance);
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/ownership/HasNoTokens.sol
    
    /**
     * @title Contracts that should not own Tokens
     * @author Remco Bloemen <remco@2π.com>
     * @dev This blocks incoming ERC223 tokens to prevent accidental loss of tokens.
     * Should tokens (any ERC20Basic compatible) end up in the contract, it allows the
     * owner to reclaim the tokens.
     */
    contract HasNoTokens is CanReclaimToken {
    
     /**
      * @dev Reject all ERC223 compatible tokens
      * @param _from address The address that is transferring the tokens
      * @param _value uint256 the amount of the specified token
      * @param _data Bytes The data passed from the caller.
      */
      function tokenFallback(
        address _from,
        uint256 _value,
        bytes _data
      )
        external
        pure
      {
        _from;
        _value;
        _data;
        revert();
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/ownership/HasNoContracts.sol
    
    /**
     * @title Contracts that should not own Contracts
     * @author Remco Bloemen <remco@2π.com>
     * @dev Should contracts (anything Ownable) end up being owned by this contract, it allows the owner
     * of this contract to reclaim ownership of the contracts.
     */
    contract HasNoContracts is Ownable {
    
      /**
       * @dev Reclaim ownership of Ownable contracts
       * @param _contractAddr The address of the Ownable to be reclaimed.
       */
      function reclaimContract(address _contractAddr) external onlyOwner {
        Ownable contractInst = Ownable(_contractAddr);
        contractInst.transferOwnership(owner);
      }
    }
    
    // File: openzeppelin-solidity/contracts/ownership/NoOwner.sol
    
    /**
     * @title Base contract for contracts that should not own things.
     * @author Remco Bloemen <remco@2π.com>
     * @dev Solves a class of errors where a contract accidentally becomes owner of Ether, Tokens or
     * Owned contracts. See respective base contracts for details.
     */
    contract NoOwner is HasNoEther, HasNoTokens, HasNoContracts {
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/DetailedERC20.sol
    
    /**
     * @title DetailedERC20 token
     * @dev The decimals are only for visualization purposes.
     * All the operations are done using the smallest and indivisible token unit,
     * just as on Ethereum all the operations are done in wei.
     */
    contract DetailedERC20 is ERC20 {
      string public name;
      string public symbol;
      uint8 public decimals;
    
      constructor(string _name, string _symbol, uint8 _decimals) public {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
      }
    }
    
    // File: openzeppelin-solidity/contracts/math/SafeMath.sol
    
    /**
     * @title SafeMath
     * @dev Math operations with safety checks that throw on error
     */
    library SafeMath {
    
      /**
      * @dev Multiplies two numbers, throws on overflow.
      */
      function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
        // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (_a == 0) {
          return 0;
        }
    
        c = _a * _b;
        assert(c / _a == _b);
        return c;
      }
    
      /**
      * @dev Integer division of two numbers, truncating the quotient.
      */
      function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
        // assert(_b > 0); // Solidity automatically throws when dividing by 0
        // uint256 c = _a / _b;
        // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
        return _a / _b;
      }
    
      /**
      * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
      */
      function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
        assert(_b <= _a);
        return _a - _b;
      }
    
      /**
      * @dev Adds two numbers, throws on overflow.
      */
      function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
        c = _a + _b;
        assert(c >= _a);
        return c;
      }
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/BasicToken.sol
    
    /**
     * @title Basic token
     * @dev Basic version of StandardToken, with no allowances.
     */
    contract BasicToken is ERC20Basic {
      using SafeMath for uint256;
    
      mapping(address => uint256) internal balances;
    
      uint256 internal totalSupply_;
    
      /**
      * @dev Total number of tokens in existence
      */
      function totalSupply() public view returns (uint256) {
        return totalSupply_;
      }
    
      /**
      * @dev Transfer token for a specified address
      * @param _to The address to transfer to.
      * @param _value The amount to be transferred.
      */
      function transfer(address _to, uint256 _value) public returns (bool) {
        require(_value <= balances[msg.sender]);
        require(_to != address(0));
    
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        emit Transfer(msg.sender, _to, _value);
        return true;
      }
    
      /**
      * @dev Gets the balance of the specified address.
      * @param _owner The address to query the the balance of.
      * @return An uint256 representing the amount owned by the passed address.
      */
      function balanceOf(address _owner) public view returns (uint256) {
        return balances[_owner];
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/BurnableToken.sol
    
    /**
     * @title Burnable Token
     * @dev Token that can be irreversibly burned (destroyed).
     */
    contract BurnableToken is BasicToken {
    
      event Burn(address indexed burner, uint256 value);
    
      /**
       * @dev Burns a specific amount of tokens.
       * @param _value The amount of token to be burned.
       */
      function burn(uint256 _value) public {
        _burn(msg.sender, _value);
      }
    
      function _burn(address _who, uint256 _value) internal {
        require(_value <= balances[_who]);
        // no need to require value <= totalSupply, since that would imply the
        // sender's balance is greater than the totalSupply, which *should* be an assertion failure
    
        balances[_who] = balances[_who].sub(_value);
        totalSupply_ = totalSupply_.sub(_value);
        emit Burn(_who, _value);
        emit Transfer(_who, address(0), _value);
      }
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/StandardToken.sol
    
    /**
     * @title Standard ERC20 token
     *
     * @dev Implementation of the basic standard token.
     * https://github.com/ethereum/EIPs/issues/20
     * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
     */
    contract StandardToken is ERC20, BasicToken {
    
      mapping (address => mapping (address => uint256)) internal allowed;
    
    
      /**
       * @dev Transfer tokens from one address to another
       * @param _from address The address which you want to send tokens from
       * @param _to address The address which you want to transfer to
       * @param _value uint256 the amount of tokens to be transferred
       */
      function transferFrom(
        address _from,
        address _to,
        uint256 _value
      )
        public
        returns (bool)
      {
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
        require(_to != address(0));
    
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        emit Transfer(_from, _to, _value);
        return true;
      }
    
      /**
       * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
       * Beware that changing an allowance with this method brings the risk that someone may use both the old
       * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
       * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       * @param _spender The address which will spend the funds.
       * @param _value The amount of tokens to be spent.
       */
      function approve(address _spender, uint256 _value) public returns (bool) {
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
      }
    
      /**
       * @dev Function to check the amount of tokens that an owner allowed to a spender.
       * @param _owner address The address which owns the funds.
       * @param _spender address The address which will spend the funds.
       * @return A uint256 specifying the amount of tokens still available for the spender.
       */
      function allowance(
        address _owner,
        address _spender
       )
        public
        view
        returns (uint256)
      {
        return allowed[_owner][_spender];
      }
    
      /**
       * @dev Increase the amount of tokens that an owner allowed to a spender.
       * approve should be called when allowed[_spender] == 0. To increment
       * allowed value is better to use this function to avoid 2 calls (and wait until
       * the first transaction is mined)
       * From MonolithDAO Token.sol
       * @param _spender The address which will spend the funds.
       * @param _addedValue The amount of tokens to increase the allowance by.
       */
      function increaseApproval(
        address _spender,
        uint256 _addedValue
      )
        public
        returns (bool)
      {
        allowed[msg.sender][_spender] = (
          allowed[msg.sender][_spender].add(_addedValue));
        emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
      }
    
      /**
       * @dev Decrease the amount of tokens that an owner allowed to a spender.
       * approve should be called when allowed[_spender] == 0. To decrement
       * allowed value is better to use this function to avoid 2 calls (and wait until
       * the first transaction is mined)
       * From MonolithDAO Token.sol
       * @param _spender The address which will spend the funds.
       * @param _subtractedValue The amount of tokens to decrease the allowance by.
       */
      function decreaseApproval(
        address _spender,
        uint256 _subtractedValue
      )
        public
        returns (bool)
      {
        uint256 oldValue = allowed[msg.sender][_spender];
        if (_subtractedValue >= oldValue) {
          allowed[msg.sender][_spender] = 0;
        } else {
          allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
        }
        emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC20/StandardBurnableToken.sol
    
    /**
     * @title Standard Burnable Token
     * @dev Adds burnFrom method to ERC20 implementations
     */
    contract StandardBurnableToken is BurnableToken, StandardToken {
    
      /**
       * @dev Burns a specific amount of tokens from the target address and decrements allowance
       * @param _from address The address which you want to send tokens from
       * @param _value uint256 The amount of token to be burned
       */
      function burnFrom(address _from, uint256 _value) public {
        require(_value <= allowed[_from][msg.sender]);
        // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted,
        // this function needs to emit an event with the updated approval.
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        _burn(_from, _value);
      }
    }
    
    // File: contracts/lifecycle/Finalizable.sol
    
    /**
     * @title Finalizable contract
     * @dev Lifecycle extension where an owner can do extra work after finishing.
     */
    contract Finalizable is Ownable {
      using SafeMath for uint256;
    
      /// @dev Throws if called before the contract is finalized.
      modifier onlyFinalized() {
        require(isFinalized, "Contract not finalized.");
        _;
      }
    
      /// @dev Throws if called after the contract is finalized.
      modifier onlyNotFinalized() {
        require(!isFinalized, "Contract already finalized.");
        _;
      }
    
      bool public isFinalized = false;
    
      event Finalized();
    
      /**
       * @dev Called by owner to do some extra finalization
       * work. Calls the contract's finalization function.
       */
      function finalize() public onlyOwner onlyNotFinalized {
        finalization();
        emit Finalized();
    
        isFinalized = true;
      }
    
      /**
       * @dev Can be overridden to add finalization logic. The overriding function
       * should call super.finalization() to ensure the chain of finalization is
       * executed entirely.
       */
      function finalization() internal {
        // override
      }
    
    }
    
    // File: contracts/token/ERC20/SafeStandardToken.sol
    
    /**
     * @title SafeStandardToken
     * @dev An ERC20 token implementation which disallows transfers to this contract.
     */
    contract SafeStandardToken is StandardToken {
    
      /// @dev Throws if destination address is not valid.
      modifier onlyValidDestination(address _to) {
        require(_to != address(this), "Transfering tokens to this contract address is not allowed.");
        _;
      }
    
      /**
       * @dev Transfer token for a specified address
       * @param _to The address to transfer to.
       * @param _value The amount to be transferred.
       */
      function transfer(address _to, uint256 _value)
        public
        onlyValidDestination(_to)
        returns (bool)
      {
        return super.transfer(_to, _value);
      }
    
      /**
       * @dev Transfer tokens from one address to another
       * @param _from address The address which you want to send tokens from
       * @param _to address The address which you want to transfer to
       * @param _value uint256 the amount of tokens to be transferred
       */
      function transferFrom(address _from, address _to, uint256 _value)
        public
        onlyValidDestination(_to)
        returns (bool)
      {
        return super.transferFrom(_from, _to, _value);
      }
    
    
    }
    
    // File: contracts/TolarToken.sol
    
    /**
     * @title TolarToken
     * @dev ERC20 Tolar Token (TOL)
     *
     * TOL Tokens are divisible by 1e18 (1 000 000 000 000 000 000) base.
     *
     * TOL are displayed using 18 decimal places of precision.
     *
     * 1 TOL is equivalent to:
     *   1 000 000 000 000 000 000 == 1 * 10**18 == 1e18
     *
     * 1 Billion TOL (total supply) is equivalent to:
     *   1000000000 * 10**18 == 1e27
     *
     * @notice All tokens are pre-assigned to the creator. Note they can later distribute these
     * tokens as they wish using `transfer` and other `StandardToken` functions.
     * This is a BurnableToken where users can burn tokens when the burning functionality is
     * enabled (contract is finalized) by the owner.
     */
    contract TolarToken is NoOwner, Finalizable, DetailedERC20, SafeStandardToken, StandardBurnableToken {
    
      string public constant NAME = "Tolar Token";
      string public constant SYMBOL = "TOL";
      uint8 public constant DECIMALS = 18;
    
      uint256 public constant INITIAL_SUPPLY = 1000000000 * (10 ** uint256(DECIMALS));
    
      /// @dev Throws if called before the contract is finalized.
      modifier onlyFinalizedOrOwner() {
        require(isFinalized || msg.sender == owner, "Contract not finalized or sender not owner.");
        _;
      }
    
      /// @dev Constructor that gives msg.sender all of existing tokens.
      constructor() public DetailedERC20(NAME, SYMBOL, DECIMALS) {
        totalSupply_ = INITIAL_SUPPLY;
        balances[msg.sender] = INITIAL_SUPPLY;
        emit Transfer(address(0), msg.sender, INITIAL_SUPPLY);
      }
    
      /**
       * @dev Overrides StandardToken._burn in order for burn and burnFrom to be disabled
       * when the contract is paused.
       */
      function _burn(address _who, uint256 _value) internal onlyFinalizedOrOwner {
        super._burn(_who, _value);
      }
    
    }