# How can i solve this error?

**URL:** <https://discuss.ampl.com/t/how-can-i-solve-this-error/2108>\
**Category:** Support\
**Tags:** displays-results, errors-and-messages, modeling\
**Created:** [April 1, 2025, 2:21pm UTC](https://discuss.ampl.com/t/how-can-i-solve-this-error/2108 "2025-04-01T14:21:54Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![edy\_munguambe](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.ampl.com/edy_munguambe/32/894_2.png) [@edy\_munguambe](https://discuss.ampl.com/u/edy_munguambe)\
**Post date:** [April 1, 2025, 2:21pm UTC](https://discuss.ampl.com/t/how-can-i-solve-this-error/2108/1 "2025-04-01T14:21:54Z")

</div>

```auto
Trabalho.mod, line 36 (offset 1790):
	syntax error
context: var >>> z1:sum{ <<< i in I} E[i] * Z[i] + sum{l in L} F[l] * W[l] + sum{i in I,k in K,j in J} (A[j] + B[j] * t_ik[i,k]) * X[i,k,j] + sum{k in K,l in L,j in J} C[j] * t_kl[k,l] * Y[k,l,j] + sum{l in L,i in I,j in J} (-G[j] + D[j] * t_li[l,i]) * S[l,i,j] + sum{l in L,j in J} (H[j] + O[j] * t_l[l]) * T[l,j];
ampl?

```

---

<div class="post-metadata">

**Author:** ![4er](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.ampl.com/4er/32/530_2.png) [@4er](https://discuss.ampl.com/u/4er)\
**Post date:** [April 2, 2025, 1:18am UTC](https://discuss.ampl.com/t/how-can-i-solve-this-error/2108/2 "2025-04-02T01:18:58Z")

</div>

It should be

```auto
var z1 = sum{i in I} E[i] * Z[i] + ...

```

This defines variable z1 by the expression to the right of the = sign.