[GNC] Whats up with this warning?

[Michael or Penny Novack]

On 12/28/2025 3:27 AM, David T. via gnucash-user wrote:
> Our you need to buy the deluxe anti-virus package...
>   
>   

That would NOT prevent all false positives. A virus checker will EITHER 
sometimes give a false positive OR sometimes fail to identify a virus 
(false negative). Since a false positive has less serious consequences 
than a missed virus, that's the side any practical virus checker should 
err on.

A virus checker that ALWAYS worked (correctly) is impossible. Impossible 
in the mathematical sense, not just "nobody has written one yet". You 
can prove this the same way Turing proved the "Fundamental Theorem of 
Computing" (that a checker that could correctly decide if a program 
would enter an endless loop). Just substitute "act like a virus" for 
"enter an endless loop" in Turing's proof.

Michael D Novack