| 2 |  | It is very useful to have che chance to change run time parameters in if-clause conditions, and in fact I was surprised that OM allowed it. I understand that the OM's OF is able to do this "by mistake". | 
          
            | 3 |  | I will use an if expression as you suggest. | 
          
            |  | 2 | It is very useful to have the chance to change run time parameters in (if-statement) if-clause conditions, and in fact I was happy, although somewhat surprised, that OM allowed it. | 
          
            |  | 3 |  | 
          
            |  | 4 | In reality in the model I have it works (using OF) like a charm. | 
          
            |  | 5 | I see that you don't see an easy way to evaluate a parameter which is used in the condition of an if statement, but this is what, at least in my example, OM's OF is able to do. | 
          
            |  | 6 | In this model I cannot use an initial equation with an if-expression since the condition I must test varies with time. | 
          
            |  | 7 |  | 
          
            |  | 8 | The rule you mention does not forbid doing what the OF already does, so I thought was an useful feature possibly coming (nearly) for free. |