In an optimization problem, rather than writing `y = maximum(x)`

, we typically would create a new slack variable called `y`

and constrain that:

```
@constraint model y .>= x
```

That will work if there is something in your objective or other constraints which is pushing “down” on `y`

. For example

```
@variable model x >= 0
(add some other constraints on x)
@variable model y
@constraint model y .>= x
@objective model Min y
```

If you can’t rely on your objective or other constraints to push down on the value of `y`

, then you have a much harder problem. You could implement that as a mixed-integer optimization, but I wouldn’t go down that road right away.