Hello,

Thanks to your help, i've got understood how to create randomly non selected choices using join, rand and substr equations.
But i still can't exclude certain options based on previously selected response.

For example, in my questionnaire, the first question asks which dish is taken (Q1). There are 4 options to choose (Meet, Seafood, Vegetarian, Vegan). According to the selected option, i want to show randomly one of the other choices (not selected ones). If Meet is chosen, Seafood or Vegetarian or Vegan appears. 

Now i'd like to exclude 'Vegan' as no choice when 'Vegetarian' is picked. I've tried to insert Q1!= to exclude but it doesn't seem to work. Could you check my file attached below ?

I would really appreciate your help.
Thank you 

 

Sorry i didn't upload the right file.
Please check the one below 

 

I fixed the problem inserting "and is_empty(Q1_subquestion code that i wanted to exclude)"

So, if "vegetarian" is chosen, there shall only appear "meat" or "seafood", but not "vegan"

Well, change the first equation to 
{join(if(is_empty(Q1_1),"A",""), if(is_empty(Q1_2),"B",""), if(is_empty(Q1_3) and is_empty(Q1_4),"C",""), if(is_empty(Q1_3) and is_empty(Q1_4),"D",""))}

You see, D=vegan is only entered if C=vegetarian was not selected and D=vegan was not selected.