Split from here.
Do you have a reference for this? Can you give any idea as to when it was supposedly borrowed?Hello,
Indeed, we use seen س as a variable (in maths, physics and chemistry).
X Y Z are rendered as س ع ص. (when you're doing chemistry or maths for instance). It is, at least, the way I was taught.
When we want to refer to someone (as X is speaking) we use فلان flaan (from fulann) in Algeria.
Interestingly fulan comes from Greek. So I think the two cultures have influenced one another a lot. It is still not clear why the Arabs used shay? for X although its meaning suggests an unkown quantity. But that's etymology and it remains speculation after all. You can never be sure about time and place of the borrowing.