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// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./interfaces/IBRC20Factory.sol";
contract BRC20 {
    string public name;
    string public symbol;
    uint8 public immutable decimals;
    address public immutable factory;
    uint256  public totalSupply;
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping(address => uint256)) public allowance;
    mapping (address => uint256) public nonces;
    bytes32 public DOMAIN_SEPARATOR;
    bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);
    constructor() {
        (name, symbol, decimals) = IBRC20Factory(msg.sender).parameters();
        factory = msg.sender;
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), keccak256(bytes('1')), chainId, address(this)));
    }
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