> On 10 Feb 2022, at 11:17 pm, raf <post...@raf.org> wrote: > > But I still don't see why it was only the second > replacement index that was out of range, and not the > first as well.
https://sciencing.com/what-is-a-counterexample-in-algebra-12750822.html ... One Counterexample Is Sufficient The philosophy of the counterexample is that if in one scenario the statement does not hold true, then the statement is false. A non-math example is "Tom has never told a lie." To show this statement is true, you have to provide "proof" that Tom has never told a lie by tracking every statement Tom has ever made. However, to disprove this statement, you only need to show one lie that Tom has ever spoken. -- Viktor.
