Re: (*) -> 1

[Michael Heerdegen]

Jean Louis <bugs@gnu.support> writes:

> I have given one example why and how I understand that function `*'
> would be more useful to yield the erorr, then 1.

Ok, one math example.

  -----        -----          -----
   | |          | |            | | 
   | | f(k)  =  | | f(k)  *    | |  f(k)
   | |          | |            | | 
m < k < n    m < k < n      m < k < n
              k prime      k not prime

Maybe the function f behaves very differently for primes and non-primes
so it's easier to compute the product like that.

But if an empty product would not be defined the whole formula would
only make sense if there are primes between n and m, and the
transformation would not be valid in the general case (since one would
always have to test for primes between n and m - for no gain).

Similar things "happen" in programming.

Michael.