memoize factorial example (was Re: decorators ?)

[Terry Reedy]

"Daniel 'Dang' Griffith" <google0 at lazytwinacres.net> wrote in message 
news:1102458244.004fc0dc548f5536ec77f769e501ff1e at teranews...
> But the factorial example on the wiki has a defect.  It incorrectly
> calculates factorial(0) as 0, when it should be 1.

This is a matter of definition, and definitions apparently differ.  fact(0) 
== 0 is a backward projection from the definition f(1) = f(2) = 1 in 
1-based systems, which is the context for the rabbit problem in which the 
first year is year 1, not year 0.  Disagreement is not defect.

Terry J. Reedy