interface IPendleBaseToken is IERC20 {
    /**
     * @notice Decreases the allowance granted to spender by the caller.
     * @param spender The address to reduce the allowance from.
     * @param subtractedValue The amount allowance to subtract.
     * @return Returns true if allowance has decreased, otherwise false.
     **/
    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);

    /**
     * @notice The yield contract start in epoch time.
     * @return Returns the yield start date.
     **/
    function start() external view returns (uint256);

    /**
     * @notice The yield contract expiry in epoch time.
     * @return Returns the yield expiry date.
     **/
    function expiry() external view returns (uint256);

    /**
     * @notice Increases the allowance granted to spender by the caller.
     * @param spender The address to increase the allowance from.
     * @param addedValue The amount allowance to add.
     * @return Returns true if allowance has increased, otherwise false
     **/
    function increaseAllowance(address spender, uint256 addedValue) external returns (bool);

    /**
     * @notice Returns the number of decimals the token uses.
     * @return Returns the token's decimals.
     **/
    function decimals() external view returns (uint8);

    /**
     * @notice Returns the name of the token.
     * @return Returns the token's name.
     **/
    function name() external view returns (string memory);

    /**
     * @notice Returns the symbol of the token.
     * @return Returns the token's symbol.
     **/
    function symbol() external view returns (string memory);

    /**
     * @notice approve using the owner's signature
     **/
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}
function decimals() external view returns (uint8);

/**
 * @notice Returns the number of decimals the token uses.
 * @return Returns the token's decimals.
 **/