[draft] "Impermanent loss" of FLI?

In ideal rebalancing case, ETH2x-FLI is thought as an extension of an asymmetric AMM, which is well formalized by Balancer team, with weight of ETH and USDC are 2 and -1, respectively.

Impermanent loss of an asymmetric AMM is also formalized by Balancer team. In 2 assets case, it can be written as:

$\frac{r^w}{1-w+wr}-1$

where $r$ is price ratio and $w$ is weight of an asset (sum of weights should be 1).

Let's consider $w=2$ case:

$\frac{r^{2}}{-1+2r}-1=\frac{(r-1)^2}{2(r-1/2)}.$

This is positive when r > 1/2.