> For the complete documentation index, see [llms.txt](https://seacows.gitbook.io/seacows-amm-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://seacows.gitbook.io/seacows-amm-docs/technical-reference/core/seacowspositionmanager/seacowserc3525.md).

# SeacowsERC3525

## What is ERC-3525?

This is a standard for semi-fungible tokens. The set of smart contract interfaces described in this document defines an [ERC-721](https://eips.ethereum.org/EIPS/eip-721) compatible token standard. This standard introduces an `<ID, SLOT, VALUE>` triple scalar model that represents the semi-fungible structure of a token. It also introduces new transfer models as well as approval models that reflect the semi-fungible nature of the tokens.

For more information, please refer to [ERC-3525](https://eips.ethereum.org/EIPS/eip-3525).

#### Benefits of using ERC-3525 as Position Management

* Storing LP shares information in NFT
* LP shares are tradable as NFT on other marketplaces.
* Using as collaterals in Lending & Borrowing protocol

#### Reference:

* <https://sftlabs.io/2023/01/06/explaining-erc-3525-what-it-is-and-how-it-works/>
* <https://eips.ethereum.org/EIPS/eip-3525>

## Mappings

### pairSlots

```solidity
mapping(address => uint256) public pairSlots;
```

To store the mapping of Pair contract address to Slot number.

### pairTokenIds

```solidity
mapping(address => uint256) public pairTokenIds;
```

To store the mapping of Pair contract address to ERC-3525 Token ID.

### slotPairs

```solidity
mapping(uint256 => address) public slotPairs;
```

To store the mapping of Slot number to Pair contract address.

## Functions

### totalValueSupplyOf

```solidity
function totalValueSupplyOf(uint256 _slot) public view virtual returns (uint256)
```

Return the Total LP Shares of a Pair by its Slot number.