# Proving the balancing score property of propensity score

• Also, answers are not to be used for asking new questions. You should have made your own question. – Noah Aug 12 '19 at 5:51
• @Noah, thank you for kind answering. You pointed out that f(x) cannot have more than one value. It makes sense now. BTW, I would have added my post as a comment if I had known that I could use math expression in the comment. :( – Royalblue Aug 12 '19 at 5:58