Brain smoker ...

[Gilles]

(12-13-2014 12:53 AM)Han Wrote:  

(12-12-2014 11:10 PM)Gilles Wrote:  Nigel idea is excellent

Another way,less efficient :

Code:


ΣLIST(|a*b|+|REVERSE(a)*b|)
or
ΣLIST(|a|*(|b|+REVERSE(|b|)))

Are you sure this works for any arbitrary lists a and b?

Any arbitrary list...of 2 elements.