Hi,

I have a complex nonlinear expression in my objective function, which occurs several times in the objective function. To make the GAMS formulation more clearer I want to replace it with an intermediate variable say

```
z(i,j) = f(z)
```

. In AMPL, I can define this as a variable relation instead of a constraint. However, in GAMS I have to write an equation. I am worried that my solver is considering this as a nonlinear constraint. Is there a way, I can avoid nonlinear constraint?