How can I prove that: $ fl(a \ op \ b) = fl(b \ op \ a), \: op = +,*.$.
I have been reading and searching the big majority say that its true. like here. However, I can not find a mathematical proof of it.
can someone give a hint of the demonstration?
This is trivial, because you have $a \ op \ b = b \ op \ a$ and therefore $fl(a \ op \ b) = fl(b \ op \ a).$