I have a parameter called z_{t, w} with the size of 2 \times 2 which is a vector of vectors.

For example, z_{1,1} and z_{2,1} are

```
z[1,1] = [10 10 30 40 50]
z[2,1] = [20 30 40]
```

I want to define a variable y based on z. The first two indices of y and z are the same. However, y has one extra index which is defined based on the length corresponding z element.

since the `length(z[1,1]) = 5`

and `length(z[2,1]) = 3`

,

Therefore, we should have

```
y[1,1,:] =
y[1,1,1]
y[1,1,2]
y[1,1,3]
y[1,1,4]
y[1,1,5]
```

and

```
y[2,1,:] =
y[2,1,1]
y[2,1,2]
y[2,1,3]
```

Is it possible to define such a variable in Julia using the JuMP package?