Mnementh said:
You cannot apply this so easily. The 'proof' you showed made the error, that the case differentiation in step 5 for divisions wasn't made. You always have to cover for the case, that you divide by zero. So step 6 and 7 are only allowed for the case A != B. But the initial statement was A=B. That cannot be applied to the first though. The only division that is made is, that something is divided by 3. We know 3 is not equal to zero. |
No, I'm making a different point here. That, a proof that looks like it 'makes sense' may actually be wrong if you don't know or realise all of the rules. I don't know enough maths to construct the reals from first principles and prove this, but I believe the words of those who can. Nothing in this thread so far is adequate proof.
