Grant Edwards schrieb: [snip]
It's the same in mathematics for many/most operators i - j and j - i aren't the same thing. The position of the variable relative to the operator tells you want's going on. While a + b is equal to b + a, that's a property of the particularoperator.OK, this is waaay off topic now...
a+b=b+a is a definition which does not have to be this way. It can be seen (in reality) but it can not be proofed (in math).
