I want to subtract the value of a process variable from a specific field and process the result by branching.

Question

I am a beginner with Appian. In the interface, I input values for each field of a record type and save them to process variables. In the process model, I want to reference the same record, subtract a specific field from the corresponding process variable, and perform the following actions: 
 If the result is 0 or below, I want to send an email without changing the value. If the result is 1 or above, I want to save the calculated result in a process variable and send an email. Can you guide me on how to achieve this in Appian?

Mounika Yalamanchili · Answer

Hi , Take a Process Variable(suppose:testVar) and store your result value in that variable(testVar) , and then place a XOR gate to navigate as per your result, if the result is 0 in pv!testVar then send mail , if it is 1 , take a script task -> in output save your pv!testVar into another if needed and then send mail. 
 Even if you want to substract or remove any value , can take script task and perform the needed action and then store the value in a variable 
 Hope you got the Answer.....