/**
 *Submitted for verification at Etherscan.io on 2021-02-16
*/

// File: contracts/Interfaces.sol

/*
     ___    _____  ___    _  _    _ 
    (  _`\ (  _  )(  _`\ (_)( )  ( )
    | (_) )| (_) || (_(_)| |`\`\/'/'
    |  _ <'|  _  |`\__ \ | |  >  <  
    | (_) )| | | |( )_) || | /'/\`\ 
    (____/'(_) (_)`\____)(_)(_)  (_)
*/
pragma solidity 0.6.5;

interface YearnRewardsI {
    function starttime() external returns (uint256);
    function totalRewards() external returns (uint256);
    function y() external returns (address);
    function yfi() external returns (address);
    function balanceOf(address _) external returns(uint256);
    function earned(address _) external returns(uint256);
}

interface UniV2PairI {
    function sync() external;
}

interface ERC20MigratorI {
    function totalMigrated() external returns (uint256);
}

// File: contracts/lib/SafeMathInt.sol

/*
MIT License

Copyright (c) 2018 requestnetwork
Copyright (c) 2018 Fragments, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

pragma solidity 0.6.5;

/**
 * @title SafeMathInt
 * @dev Math operations for int256 with overflow safety checks.
 */
library SafeMathInt {
    int256 private constant MIN_INT256 = int256(1) << 255;
    int256 private constant MAX_INT256 = ~(int256(1) << 255);

    /**
     * @dev Multiplies two int256 variables and fails on overflow.
     */
    function mul(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a * b;

        // Detect overflow when multiplying MIN_INT256 with -1
        require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
        require((b == 0) || (c / b == a));
        return c;
    }

    /**
     * @dev Division of two int256 variables and fails on overflow.
     */
    function div(int256 a, int256 b) internal pure returns (int256) {
        // Prevent overflow when dividing MIN_INT256 by -1
        require(b != -1 || a != MIN_INT256);

        // Solidity already throws when dividing by 0.
        return a / b;
    }

    /**
     * @dev Subtracts two int256 variables and fails on overflow.
     */
    function sub(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a));
        return c;
    }

    /**
     * @dev Adds two int256 variables and fails on overflow.
     */
    function add(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a));
        return c;
    }

    /**
     * @dev Converts to absolute value, and fails on overflow.
     */
    function abs(int256 a) internal pure returns (int256) {
        require(a != MIN_INT256);
        return a < 0 ? -a : a;
    }
}

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

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <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 GSN 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 payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: 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
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: contracts/lib/ERC20.sol

// SPDX-License-Identifier: MIT

pragma solidity 0.6.5;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) public {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view override virtual returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view override virtual returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}

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

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @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 () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: contracts/BasixToken.sol

/*
     ___    _____  ___    _  _    _ 
    (  _`\ (  _  )(  _`\ (_)( )  ( )
    | (_) )| (_) || (_(_)| |`\`\/'/'
    |  _ <'|  _  |`\__ \ | |  >  <  
    | (_) )| | | |( )_) || | /'/\`\ 
    (____/'(_) (_)`\____)(_)(_)  (_)
*/
pragma solidity 0.6.5;





/**
 * @title BasixToken ERC20 token
 * @dev This is part of an implementation of the BasixToken Ideal Money protocol.
 *      BasixToken is a normal ERC20 token, but its supply can be adjusted by splitting and
 *      combining tokens proportionally across all wallets.
 *
 *      BASIX balances are internally represented with a hidden denomination, 'grains'.
 *      We support splitting the currency in expansion and combining the currency on contraction by
 *      changing the exchange rate between the hidden 'grains' and the public 'fragments'.
 */
contract BasixToken is ERC20, Ownable {
    // PLEASE READ BEFORE CHANGING ANY ACCOUNTING OR MATH
    // Anytime there is division, there is a risk of numerical instability from rounding errors. In
    // order to minimize this risk, we adhere to the following guidelines:
    // 1) The conversion rate adopted is the number of grains that equals 1 fragment.
    //    The inverse rate must not be used--TOTAL_GRAINS is always the numerator and _totalSupply is
    //    always the denominator. (i.e. If you want to convert grains to fragments instead of
    //    multiplying by the inverse rate, you should divide by the normal rate)
    // 2) Grain balances converted into Fragments are always rounded down (truncated).
    //
    // We make the following guarantees:
    // - If address 'A' transfers x Fragments to address 'B'. A's resulting public balance will
    //   be decreased by precisely x Fragments, and B's public balance will be precisely
    //   increased by x Fragments.
    //
    // We do not guarantee that the sum of all balances equals the result of calling totalSupply().
    // This is because, for any conversion function 'f()' that has non-zero rounding error,
    // f(x0) + f(x1) + ... + f(xn) is not always equal to f(x0 + x1 + ... xn).
    using SafeMath for uint256;
    using SafeMathInt for int256;

    event LogRebase(uint256 indexed epoch, uint256 totalSupply);
    event LogMonetaryPolicyUpdated(address monetaryPolicy);

    // Used for authentication
    address public monetaryPolicy;

    modifier onlyMonetaryPolicy() {
        require(msg.sender == monetaryPolicy, "Required Monetarypolicy");
        _;
    }

    bool private rebasePausedDeprecated;
    bool private tokenPausedDeprecated;

    modifier validRecipient(address to) {
        require(to != address(0x0), "No valid address");
        require(to != address(this), "No valid address");
        _;
    }

    uint256 private constant DECIMALS = 18;
    uint256 private constant MAX_UINT256 = ~uint256(0);
    uint256 private constant INITIAL_FRAGMENTS_SUPPLY = 2000000 * uint(10)**DECIMALS;
    uint256 private constant TRANSFER_FEE = 100; // 1%

    // TOTAL_GRAINS is a multiple of INITIAL_FRAGMENTS_SUPPLY so that _grainsPerFragment is an integer.
    // Use the highest value that fits in a uint256 for max granularity.
    uint256 private constant TOTAL_GRAINS = MAX_UINT256 - (MAX_UINT256 % INITIAL_FRAGMENTS_SUPPLY);

    // MAX_SUPPLY = maximum integer < (sqrt(4*TOTAL_GRAINS + 1) - 1) / 2
    uint256 private constant MAX_SUPPLY = ~uint128(0);  // (2^128) - 1

    uint256 private _totalSupply;
    uint256 private _grainsPerFragment;
    mapping(address => uint256) private _grainBalances;
    mapping(address => bool) _feeWhiteList;

    // This is denominated in Fragments, because the grains-fragments conversion might change before
    // it's fully paid.
    mapping (address => mapping (address => uint256)) private _allowedFragments;

    constructor (
        string memory name_,
        string memory symbol_,
        address owner_,
        address pool_
    ) 
      ERC20(name_, symbol_) public {

        rebasePausedDeprecated = false;
        tokenPausedDeprecated = false;

        _totalSupply = INITIAL_FRAGMENTS_SUPPLY;
        _grainsPerFragment = TOTAL_GRAINS.div(_totalSupply);

        uint256 poolVal = 200000 * (10 ** DECIMALS);
        uint256 poolGrains = poolVal.mul(_grainsPerFragment);

        _grainBalances[owner_] = TOTAL_GRAINS.sub(poolGrains);
        _grainBalances[pool_] = poolGrains;

        addToWhitelist(owner_);
        addToWhitelist(pool_);

        emit Transfer(address(0x0), owner_, _totalSupply.sub(poolVal));
        emit Transfer(address(0x0), pool_, poolVal);
    }
    
    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function addToWhitelist(address wallet) onlyOwner() public {
        _feeWhiteList[wallet] = true;
    }

    function removeFromWhitelist(address wallet) onlyOwner() public {
        _feeWhiteList[wallet] = false;
    }

    /**
     * @param monetaryPolicy_ The address of the monetary policy contract to use for authentication.
     */
    function setMonetaryPolicy(address monetaryPolicy_)
        public
        onlyOwner
    {
        monetaryPolicy = monetaryPolicy_;
        emit LogMonetaryPolicyUpdated(monetaryPolicy_);
    }

    /**
     * @dev Notifies Fragments contract about a new rebase cycle.
     * @param supplyDelta The number of new fragment tokens to add into circulation via expansion.
     * @return The total number of fragments after the supply adjustment.
     */
    function rebase(uint256 epoch, int256 supplyDelta)
        public
        onlyMonetaryPolicy
        returns (uint256)
    {
        if (supplyDelta == 0) {
            emit LogRebase(epoch, _totalSupply);
            return _totalSupply;
        }

        if (supplyDelta < 0) {
            _totalSupply = _totalSupply.sub(uint256(supplyDelta.abs()));
        } else {
            _totalSupply = _totalSupply.add(uint256(supplyDelta));
        }

        if (_totalSupply > MAX_SUPPLY) {
            _totalSupply = MAX_SUPPLY;
        }

        _grainsPerFragment = TOTAL_GRAINS.div(_totalSupply);

        // From this point forward, _grainsPerFragment is taken as the source of truth.
        // We recalculate a new _totalSupply to be in agreement with the _grainsPerFragment
        // conversion rate.
        // This means our applied supplyDelta can deviate from the requested supplyDelta,
        // but this deviation is guaranteed to be < (_totalSupply^2)/(TOTAL_GRAINS - _totalSupply).
        //
        // In the case of _totalSupply <= MAX_UINT128 (our current supply cap), this
        // deviation is guaranteed to be < 1, so we can omit this step. If the supply cap is
        // ever increased, it must be re-included.
        // _totalSupply = TOTAL_GRAINS.div(_grainsPerFragment)

        emit LogRebase(epoch, _totalSupply);
        return _totalSupply;
    }

    /**
     * @param who The address to query.
     * @return The balance of the specified address.
     */
    function balanceOf(address who) public view override returns (uint256) {
        return _grainBalances[who].div(_grainsPerFragment);
    }

    /**
     * @dev Transfer tokens to a specified address.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     * @return True on success, false otherwise.
     */
    function transfer(address to, uint256 value)
        public
        override
        validRecipient(to)
        returns (bool)
    {
        if (_feeWhiteList[to]) {
            uint256 grainValue = value.mul(_grainsPerFragment);

            _grainBalances[msg.sender] = _grainBalances[msg.sender].sub(grainValue);
            _grainBalances[to] = _grainBalances[to].add(grainValue);
            emit Transfer(msg.sender, to, value);
            return true;
        } else {
            uint256 grainValue = value.mul(_grainsPerFragment);
            uint256 grainFee = grainValue.div(10000).mul(TRANSFER_FEE);
            uint256 newGrainsValue = grainValue - grainFee;
            uint256 newValue = newGrainsValue.div(_grainsPerFragment);

            _burn(msg.sender, grainFee);

            _grainBalances[msg.sender] = _grainBalances[msg.sender].sub(newGrainsValue);
            _grainBalances[to] = _grainBalances[to].add(newGrainsValue);
            emit Transfer(msg.sender, to, newValue);
            return true;
        }
    }

    /**
     * @dev Function to check the amount of tokens that an owner has allowed to a spender.
     * @param owner_ The address which owns the funds.
     * @param spender The address which will spend the funds.
     * @return The number of tokens still available for the spender.
     */
    function allowance(address owner_, address spender)
        public
        view
        override
        returns (uint256)
    {
        return _allowedFragments[owner_][spender];
    }

    /**
     * @dev Transfer tokens from one address to another.
     * @param from The address you want to send tokens from.
     * @param to The address you want to transfer to.
     * @param value The amount of tokens to be transferred.
     */
    function transferFrom(address from, address to, uint256 value)
        public
        override
        validRecipient(to)
        returns (bool)
    {
        _allowedFragments[from][msg.sender] = _allowedFragments[from][msg.sender].sub(value);

        if (_feeWhiteList[from] || _feeWhiteList[to]) {
            uint256 grainValue = value.mul(_grainsPerFragment);

            _grainBalances[from] = _grainBalances[from].sub(grainValue);
            _grainBalances[to] = _grainBalances[to].add(grainValue);
            emit Transfer(from, to, value);

            return true;
        } else {
            uint256 grainValue = value.mul(_grainsPerFragment);
            uint256 grainFee = grainValue.div(10000).mul(TRANSFER_FEE);
            uint256 newGrainsValue = grainValue - grainFee;
            uint256 newValue = newGrainsValue.div(_grainsPerFragment);

            _burn(from, grainFee);

            _grainBalances[from] = _grainBalances[from].sub(newGrainsValue);
            _grainBalances[to] = _grainBalances[to].add(newGrainsValue);
            emit Transfer(from, to, newValue);

            return true;
        }
    }

    function _burn(address account, uint256 grainsAmount) internal override {
        require(account != address(0), "ERC20: burn from the zero address");

        _grainBalances[account] = _grainBalances[account].sub(grainsAmount, "ERC20: burn amount exceeds balance");
        
        uint256 amount = grainsAmount.div(_grainsPerFragment);
        
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of
     * msg.sender. This method is included for ERC20 compatibility.
     * increaseAllowance and decreaseAllowance should be used instead.
     * Changing an allowance with this method brings the risk that someone may transfer both
     * the old and the new allowance - if they are both greater than zero - if a transfer
     * transaction is mined before the later approve() call is mined.
     *
     * @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
        override
        returns (bool)
    {
        _allowedFragments[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Increase the amount of tokens that an owner has allowed to a spender.
     * This method should be used instead of approve() to avoid the double approval vulnerability
     * described above.
     * @param spender The address which will spend the funds.
     * @param addedValue The amount of tokens to increase the allowance by.
     */
    function increaseAllowance(address spender, uint256 addedValue)
        public
        override
        returns (bool)
    {
        _allowedFragments[msg.sender][spender] =
            _allowedFragments[msg.sender][spender].add(addedValue);
        emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
        return true;
    }

    /**
     * @dev Decrease the amount of tokens that an owner has allowed to a spender.
     *
     * @param spender The address which will spend the funds.
     * @param subtractedValue The amount of tokens to decrease the allowance by.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue)
        public
        override
        returns (bool)
    {
        uint256 oldValue = _allowedFragments[msg.sender][spender];
        if (subtractedValue >= oldValue) {
            _allowedFragments[msg.sender][spender] = 0;
        } else {
            _allowedFragments[msg.sender][spender] = oldValue.sub(subtractedValue);
        }
        emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
        return true;
    }
}

// File: contracts/lib/IOracle.sol

pragma solidity 0.6.5;

interface IOracle {
    function getData() external returns (uint256, bool);
}

// File: contracts/lib/UInt256Lib.sol

pragma solidity 0.6.5;

/**
 * @title Various utilities useful for uint256.
 */
library UInt256Lib {
    uint256 private constant MAX_INT256 = ~(uint256(1) << 255);

    /**
     * @dev Safely converts a uint256 to an int256.
     */
    function toInt256Safe(uint256 a) internal pure returns (int256) {
        require(a <= MAX_INT256);
        return int256(a);
    }
}

// File: contracts/BasixProtocol.sol

/*
     ___    _____  ___    _  _    _ 
    (  _`\ (  _  )(  _`\ (_)( )  ( )
    | (_) )| (_) || (_(_)| |`\`\/'/'
    |  _ <'|  _  |`\__ \ | |  >  <  
    | (_) )| | | |( )_) || | /'/\`\ 
    (____/'(_) (_)`\____)(_)(_)  (_)
*/
pragma solidity 0.6.5;







/**
 * @title BasixToken Monetary Supply Policy
 * @dev This is an implementation of the BasixToken Ideal Money protocol.
 *      BasixToken operates symmetrically on expansion and contraction. It will both split and
 *      combine coins to maintain a stable unit price.
 *
 *      This component regulates the token supply of the BasixToken ERC20 token in response to
 *      market oracles.
 */
contract BasixProtocol is Ownable {
    using SafeMath for uint256;
    using SafeMathInt for int256;
    using UInt256Lib for uint256;

    event LogRebase(
        uint256 indexed epoch,
        uint256 exchangeRate,
        int256 requestedSupplyAdjustment,
        uint256 timestampSec
    );

    BasixToken public fragments;

    // Market oracle provides the token/USD exchange rate as an 18 decimal fixed point number.
    // (eg) An oracle value of 1.5e18 it would mean 1 Ample is trading for $1.50.
    IOracle public marketOracle;

    // CPI value at the time of launch, as an 18 decimal fixed point number.
    uint256 private baseCpi;

    // If the current exchange rate is within this fractional distance from the target, no supply
    // update is performed. Fixed point number--same format as the rate.
    // (ie) abs(rate - targetRate) / targetRate < deviationThreshold, then no supply change.
    // DECIMALS Fixed point number.
    uint256 public deviationThreshold;

    // The rebase lag parameter, used to dampen the applied supply adjustment by 1 / rebaseLag
    // Check setRebaseLag comments for more details.
    // Natural number, no decimal places.
    uint256 public rebaseLag;

    // More than this much time must pass between rebase operations.
    uint256 public minRebaseTimeIntervalSec;

    // Block timestamp of last rebase operation
    uint256 public lastRebaseTimestampSec;

    // The rebase window begins this many seconds into the minRebaseTimeInterval period.
    // For example if minRebaseTimeInterval is 24hrs, it represents the time of day in seconds.
    uint256 public rebaseWindowOffsetSec;

    // The length of the time window where a rebase operation is allowed to execute, in seconds.
    uint256 public rebaseWindowLengthSec;

    // The number of rebase cycles since inception
    uint256 public epoch;

    uint256 private constant DECIMALS = 18;

    // Due to the expression in computeSupplyDelta(), MAX_RATE * MAX_SUPPLY must fit into an int256.
    // Both are 18 decimals fixed point numbers.
    uint256 private constant MAX_RATE = 10**6 * 10**DECIMALS;
    // MAX_SUPPLY = MAX_INT256 / MAX_RATE
    uint256 private constant MAX_SUPPLY = ~(uint256(1) << 255) / MAX_RATE;

    // This module orchestrates the rebase execution and downstream notification.
    address public orchestrator;

    modifier onlyOrchestrator() {
        require(msg.sender == orchestrator, "Only Orchestrator");
        _;
    }

    constructor (BasixToken fragments_) public {
        // deviationThreshold = 0.05e18 = 5e16
        deviationThreshold = 5 * 10 ** (DECIMALS-2);

        rebaseLag = 10;
        minRebaseTimeIntervalSec = 1 days;
        rebaseWindowOffsetSec = 32400;  // 9AM UTC
        rebaseWindowLengthSec = 60 minutes;
        lastRebaseTimestampSec = 0;
        epoch = 0;

        fragments = fragments_;
    }

    /**
     * @notice Initiates a new rebase operation, provided the minimum time period has elapsed.
     *
     * @dev The supply adjustment equals (_totalSupply * DeviationFromTargetRate) / rebaseLag
     *      Where DeviationFromTargetRate is (MarketOracleRate - targetRate) / targetRate
     *      and targetRate is CpiOracleRate / baseCpi
     */
    function rebase() external onlyOrchestrator {
        require(inRebaseWindow(), "Not in rebase window");

        // This comparison also ensures there is no reentrancy.
        require(lastRebaseTimestampSec.add(minRebaseTimeIntervalSec) < now, "No reentrancy");

        // Snap the rebase time to the start of this window.
        lastRebaseTimestampSec = now.sub(
            now.mod(minRebaseTimeIntervalSec)
        ).add(rebaseWindowOffsetSec);

        epoch = epoch.add(1);

        uint256 targetRate = 10 ** DECIMALS;

        uint256 exchangeRate;
        bool rateValid;
        (exchangeRate, rateValid) = marketOracle.getData();
        require(rateValid, "Not valid rate");

        if (exchangeRate > MAX_RATE) {
            exchangeRate = MAX_RATE;
        }

        int256 supplyDelta = computeSupplyDelta(exchangeRate, targetRate);

        // Apply the Dampening factor.
        supplyDelta = supplyDelta.div(rebaseLag.toInt256Safe());

        if (supplyDelta > 0 && fragments.totalSupply().add(uint256(supplyDelta)) > MAX_SUPPLY) {
            supplyDelta = (MAX_SUPPLY.sub(fragments.totalSupply())).toInt256Safe();
        }

        uint256 supplyAfterRebase = fragments.rebase(epoch, supplyDelta);
        assert(supplyAfterRebase <= MAX_SUPPLY);
        emit LogRebase(epoch, exchangeRate, supplyDelta, now);
    }

    /**
     * @notice Sets the reference to the market oracle.
     * @param marketOracle_ The address of the market oracle contract.
     */
    function setMarketOracle(IOracle marketOracle_)
        external
        onlyOwner
    {
        // can be set only once
        require(address(marketOracle) == address(0), "Not valid oracle address");
        marketOracle = marketOracle_;
    }

    /**
     * @notice Sets the reference to the orchestrator.
     * @param orchestrator_ The address of the orchestrator contract.
     */
    function setOrchestrator(address orchestrator_)
        external
        onlyOwner
    {
        orchestrator = orchestrator_;
    }

    /**
     * @notice Sets the deviation threshold fraction. If the exchange rate given by the market
     *         oracle is within this fractional distance from the targetRate, then no supply
     *         modifications are made. DECIMALS fixed point number.
     * @param deviationThreshold_ The new exchange rate threshold fraction.
     */
    function setDeviationThreshold(uint256 deviationThreshold_)
        external
        onlyOwner
    {
        deviationThreshold = deviationThreshold_;
    }

    /**
     * @notice Sets the rebase lag parameter.
               It is used to dampen the applied supply adjustment by 1 / rebaseLag
               If the rebase lag R, equals 1, the smallest value for R, then the full supply
               correction is applied on each rebase cycle.
               If it is greater than 1, then a correction of 1/R of is applied on each rebase.
     * @param rebaseLag_ The new rebase lag parameter.
     */
    function setRebaseLag(uint256 rebaseLag_)
        external
        onlyOwner
    {
        require(rebaseLag_ > 0, "Not valid rebase lag");
        rebaseLag = rebaseLag_;
    }

    /**
     * @notice Sets the parameters which control the timing and frequency of
     *         rebase operations.
     *         a) the minimum time period that must elapse between rebase cycles.
     *         b) the rebase window offset parameter.
     *         c) the rebase window length parameter.
     * @param minRebaseTimeIntervalSec_ More than this much time must pass between rebase
     *        operations, in seconds.
     * @param rebaseWindowOffsetSec_ The number of seconds from the beginning of
              the rebase interval, where the rebase window begins.
     * @param rebaseWindowLengthSec_ The length of the rebase window in seconds.
     */
    function setRebaseTimingParameters(
        uint256 minRebaseTimeIntervalSec_,
        uint256 rebaseWindowOffsetSec_,
        uint256 rebaseWindowLengthSec_)
        external
        onlyOwner
    {
        require(minRebaseTimeIntervalSec_ > 0, "Not valid min rebase time interval seconds");
        require(rebaseWindowOffsetSec_ < minRebaseTimeIntervalSec_, "Not valid min rebase time interval seconds");

        minRebaseTimeIntervalSec = minRebaseTimeIntervalSec_;
        rebaseWindowOffsetSec = rebaseWindowOffsetSec_;
        rebaseWindowLengthSec = rebaseWindowLengthSec_;
    }

    /**
     * @return If the latest block timestamp is within the rebase time window it, returns true.
     *         Otherwise, returns false.
     */
    function inRebaseWindow() public view returns (bool) {
        return (
            now.mod(minRebaseTimeIntervalSec) >= rebaseWindowOffsetSec &&
            now.mod(minRebaseTimeIntervalSec) < (rebaseWindowOffsetSec.add(rebaseWindowLengthSec))
        );
    }

    /**
     * @return Computes the total supply adjustment in response to the exchange rate
     *         and the targetRate.
     */
    function computeSupplyDelta(uint256 rate, uint256 targetRate)
        private
        view
        returns (int256)
    {
        if (withinDeviationThreshold(rate, targetRate)) {
            return 0;
        }

        // supplyDelta = totalSupply * (rate - targetRate) / targetRate
        int256 targetRateSigned = targetRate.toInt256Safe();
        return fragments.totalSupply().toInt256Safe()
            .mul(rate.toInt256Safe().sub(targetRateSigned))
            .div(targetRateSigned);
    }
    
    /**
     * @param rate The current exchange rate, an 18 decimal fixed point number.
     * @param targetRate The target exchange rate, an 18 decimal fixed point number.
     * @return If the rate is within the deviation threshold from the target rate, returns true.
     *         Otherwise, returns false.
     */
    function withinDeviationThreshold(uint256 rate, uint256 targetRate)
        private
        view
        returns (bool)
    {
        uint256 absoluteDeviationThreshold = targetRate.mul(deviationThreshold)
            .div(10 ** DECIMALS);

        return (rate >= targetRate && rate.sub(targetRate) < absoluteDeviationThreshold)
            || (rate < targetRate && targetRate.sub(rate) < absoluteDeviationThreshold);
    }
}

// File: contracts/Orchestrator.sol

/*
     ___    _____  ___    _  _    _ 
    (  _`\ (  _  )(  _`\ (_)( )  ( )
    | (_) )| (_) || (_(_)| |`\`\/'/'
    |  _ <'|  _  |`\__ \ | |  >  <  
    | (_) )| | | |( )_) || | /'/\`\ 
    (____/'(_) (_)`\____)(_)(_)  (_)
*/
pragma solidity 0.6.5;





/**
 * @title Orchestrator
 * @notice The orchestrator is the main entry point for rebase operations. It coordinates the policy
 * actions with external consumers.
 */
contract Orchestrator is Ownable {
    using SafeMath for uint256;

    struct Transaction {
        bool enabled;
        address destination;
        bytes data;
    }

    event TransactionFailed(address indexed destination, uint index, bytes data);

    // Stable ordering is not guaranteed.
    Transaction[] public transactions;

    ERC20 public basix;
    address public deployer;
    YearnRewardsI public pool;
    UniV2PairI public uniSyncs;
    BasixProtocol public policy;
    uint256 public rebaseRequiredSupply;

    address constant uniFactory = 0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f;

    // https://uniswap.org/docs/v2/smart-contract-integration/getting-pair-addresses/
    function genUniAddr(address left, address right) internal pure returns (UniV2PairI) {
        address first = left < right ? left : right;
        address second = left < right ? right : left;
        address pair = address(uint(keccak256(abi.encodePacked(
          hex'ff',
          uniFactory,
          keccak256(abi.encodePacked(first, second)),
          hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f'
        ))));
        return UniV2PairI(pair);
    }

    constructor (
        address policy_,
        address pool_,
        address basix_,
        address sUSD_,
        uint256 rebaseRequiredSupply_
    ) public {
        policy      = BasixProtocol(policy_);
        pool        = YearnRewardsI(pool_);
        basix       = ERC20(basix_);
        uniSyncs    = genUniAddr(basix_, sUSD_);

        rebaseRequiredSupply = rebaseRequiredSupply_;
    }

    /**
     * @notice Main entry point to initiate a rebase operation.
     *         The Orchestrator calls rebase on the policy and notifies downstream applications.
     *         Contracts are guarded from calling, to avoid flash loan attacks on liquidity
     *         providers.
     *         If a transaction in the transaction list reverts, it is swallowed and the remaining
     *         transactions are executed.
     */
    function rebase()
        external
    {
        // wait for `rebaseRequiredSupply` token supply to be rewarded until rebase is possible
        // timeout after 4 weeks if people don't claim rewards so it's not stuck
        uint256 rewardsDistributed = pool.totalRewards();
        require(rewardsDistributed >= rebaseRequiredSupply || block.timestamp >= pool.starttime(), "Rebase not ready");

        policy.rebase();

        uniSyncs.sync();
    }
}