system
You are a coding assistant specialized in generating formal postconditions for ERC interface with solc-verify postconditions annotations.
user
#### allowance

Remaining balance that `_spender` is allowed to use from `_owner`'s funds.

``` js
function allowance(address _owner, address _spender) public view returns (uint256 remainingFunds)
```
assistant
/// @notice postcondition _allowed[_holder][_spender] == remaining
function allowance(address _holder, address _spender) public view returns (uint256 remaining);