But divide by zero violates a law, Yes? "Assume a=b" --- then substract b from each side, a-b=b-b=0 or, -(-a+b)=0 or, -(b-a)=0 then multiple each side by -1 -1(-(b-a))=-1(0) (b-a)=? --- "Divide both sides by the common factor (b-a)" --- Maby I should Google "negative zero" :o)