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IERC20PermitAllowed
Interface used by DAI/CHAI for permit
Functions
permit
  function permit(
    address holder,
    address spender,
    uint256 nonce,
    uint256 expiry,
    bool allowed,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external
Approve the spender to spend some tokens via the holder signature
This is the permit interface used by DAI and CHAI
Parameters:
| Name | Type | Description | 
|---|---|---|
| holder | address | The address of the token holder, the token owner | 
| spender | address | The address of the token spender | 
| nonce | uint256 | The holder's nonce, increases at each call to permit | 
| expiry | uint256 | The timestamp at which the permit is no longer valid | 
| allowed | bool | Boolean that sets approval amount, true for type(uint256).max and false for 0 | 
| v | uint8 | Must produce valid secp256k1 signature from the holder along with rands | 
| r | bytes32 | Must produce valid secp256k1 signature from the holder along with vands | 
| s | bytes32 | Must produce valid secp256k1 signature from the holder along with randv |