// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2;

/// @dev Interface of the ERC20 standard as defined in the EIP.

/// @dev This includes the optional name, symbol, and decimals metadata.

interface IERC20 {

    /// @dev Emitted when `value` tokens are moved from one account (`from`) to another (`to`).

    event Transfer(address indexed from, address indexed to, uint256 value);

    /// @dev Emitted when the allowance of a `spender` for an `owner` is set, where `value`

    /// is the new allowance.

    event Approval(address indexed owner, address indexed spender, uint256 value);

    /// @notice Returns the amount of tokens in existence.

    function totalSupply() external view returns (uint256);

    /// @notice Returns the amount of tokens owned by `account`.

    function balanceOf(address account) external view returns (uint256);

    /// @notice Moves `amount` tokens from the caller's account to `to`.

    function transfer(address to, uint256 amount) external returns (bool);

    /// @notice Returns the remaining number of tokens that `spender` is allowed

    /// to spend on behalf of `owner`

    function allowance(address owner, address spender) external view returns (uint256);

    /// @notice Sets `amount` as the allowance of `spender` over the caller's tokens.

    /// @dev Be aware of front-running risks: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729

    function approve(address spender, uint256 amount) external returns (bool);

    /// @notice Moves `amount` tokens from `from` to `to` using the allowance mechanism.

    /// `amount` is then deducted from the caller's allowance.

    function transferFrom(address from, address to, uint256 amount) external returns (bool);

    /// @notice Returns the name of the token.

    function name() external view returns (string memory);

    /// @notice Returns the symbol of the token.

    function symbol() external view returns (string memory);

    /// @notice Returns the decimals places of the token.

    function decimals() external view returns (uint8);

}