same as +A = + B. (rule 1) +A = + Bis the same as -B = - A (rule 2 done twice) -B = -A is the same as B = A (rule 3) Success. So A= Bis the same as B= A. I have my proof. It might be glaringly obvious, but that’s not the point. The point is you can apply rules to symbols and derive new rules. It does