u@v - u should be applied to v-cells. This should happen before the result of v is filled and reshaped.

For example we should have:

    (<@(i."0)) 4 2
┌───────┬───┐
│0 1 2 3│0 1│
└───────┴───┘

But the current implementation of @ returns a different result as (i."0) 4 2 returns a padded array of shape 4 2 before < is applied. We need to apply < to 0 1 2 3 and 0 1.