product() unexpected result

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The math function product() is giving me an unexpected result when the input is an empty sequence.

I test the function as follows: 

object void 
 
 
void = {6,6,4,3} 
? void 
void = product(void) 
? void 
puts(1, EOL) 
 
void = {6,0,4,3} 
? void 
void = product(void) 
? void 
puts(1, EOL) 
 
void = {0,0,0,0} 
? void 
void = product(void) 
? void 
puts(1,EOL) 
 
void = {} 
? void 
void = product(void) 
? void 
puts(1, EOL)

This is the result: 

{6,6,4,3} 
432 
 
{6,0,4,3} 
0 
 
{0,0,0,0} 
0 
 
{} 
1

The last case is giving what is, in my case, a wrong answer.

I can see why the function does this, and understand why the variable b is set to 1 to make the function work. But it's not the result I expect, or want.

I've modified my own version of the routine as follows: 

if atom(a) then 
	return a 
elsif length(a)  = 0 then     -- CW add 
	return 0              -- CW add 
end if

Any other thoughts on this ? As always, what is obvious to me might be misguided, I might be missing some bigger picture.

Craig

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