How Do We Talk to Aliens?

If there are any ligent aliens, and if they exist, we could ever get in contact with them. The only way to proceed would be to try to find some common ground. An article by morvan minsky suggested that maybe if an intelligence existed somewhere, they would at least have the successor function. If you can take the simplest possible human language, one which has only one word in its vocabulary,  you basically get the successor function of a computer system. So maybe there's a point of contact these systems. Also, a little bit of tweaking give you arithmetic. so maybe that's a broader point of contact.