How can i solve this error?

Support
, ,
1 
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?
2

It should be

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

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