## add_liquidity We'll quickly outline the function `add_liquidity` before we look at the code. The first step inside the `add_liquidity` function is to calculate the `imbalance_fee_multiplier`. This is how we discourage users from adding too much of one token, potentially causing the pool to become imbalanced. The function then calculates the `A` parameter, which is a parameter of the pool. Next, we calculate the current liquidity of the pool, which we refer to as `D0`. After this, the function transfers the tokens into the pool. Then the token balances are updated. At this stage, this happens in memory rather than updating the state variables, which saves gas. Next, we calculate the liquidity again, now with the transferred tokens added, and we call this `D1`. Now that we have `D0` and `D1`, we calculate the imbalance fee. After calculating the imbalance fee, we once again calculate the liquidity, this time after removing the imbalance fee, which we call `D2`. Finally, we update the token balances, this time updating the state variables, because we now have the final balances, and we need to update the pool's state. Finally, we calculate the LP shares for the liquidity provider and mint LP tokens. ## Code Block Examples Here's an example of the `D0` calculation: ```javascript function calculateLiquidityD0(tokens) { let D = 0; for (let i = 0; i < tokens.length; i++) { D = D + tokens[i]; } return D; } ``` And an example of the code that updates the token balances in the pool's storage: ```javascript function updateTokenBalances(tokenBalances, updatedBalances) { for (let i = 0; i < tokenBalances.length; i++) { tokenBalances[i] = updatedBalances[i]; } } ```