Hi,
I have to use the if statement for my model. But I get an error for this equation. Why didn’t I get the error? I’d appreciate it if you could help.

37 ‘=l=’ or ‘=e=’ or ‘=g=’ operator expected
409 Unrecognizable item - skip to find a new statement
looking for a ‘;’ or a key word to get started again

Thanks your answer. I’ve solved this problem, but I have another problem. I couldn’t figure out how to write this equation because the variables for the following constraint cannot be written into the if statement (dollar condition). If the second index of Q is 4, I want that value to be 0 if this index is 10. How can I do it ? I’d appreciate it if you could.