>>Gerry-
>>
>>>"Theoretically" it is possible to have bug free code. Given enough time, _anything_ is possible; eg. "Big Bang".
>>
>>Nope. Impossible to _prove_. Impossible to test in all contexts on all systems under all conditions. Even your example. However, I did qualify my comments to Jim by saying a program of sufficient complexity to be useful.
>
>I'll give you a function that's possible to prove that may look impossible. Try this (very simple)

FUNCTION AddTwo
>  LPARAMETERS tnOne, tnTwo
>
>  RETURN tnOne + tnTwo
>ENDFUNC

Hi George,

I suppose you considered the possibility of errors that would result from calling this function with a non-numeric argument, or with 2 numbers whose magnitude would produce an overflow. The failure to check for these cases might be regarded as a bug, or should we conclude that it will suffice in general simply to throw an error and leave the consequences to an all-knowing error handler?

Mike