Participation Certifcates (PC)

Participation Certificates are project tokens that are not transferrable. They represent receivables for future deliverable assets.

Function

A PC is created exactly once (issuance) and destroyed once (redemption). It is not transferrable.

Purpose

The PC is an illiquid asset. In the early stages of a project, it is not desirable to have a market created for tokens.

Motivation

To avoid adding a pause function to standard ERC20, the cleaner approach is to split the financing and issuance into two stages.

Details

name symbol decimals _issue _redeem

Implementation

uint256 private _totalSupply; mapping (address => uint256) private _balances;

/** @dev Creates `amount` tokens and assigns them to `account`, increasing
    * the total supply.
*/
function _issue(address account, uint256 amount) internal virtual {
    require(account != address(0), "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);
}

function _redeem(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);
}

munair/pc.md