Re: object algebra
Date: Sun, 29 Feb 2004 18:13:20 GMT
Message-ID: <4Zp0c.149745$uV3.687129_at_attbi_s51>
"Neo" <neo55592_at_hotmail.com> wrote in message news:4b45d3ad.0402290711.6bdb201_at_posting.google.com...
> > Anyway, that response shows the boy falls clearly (as do you) into
> > the group of people who are not comfortable with nullary logic.
>
> Isn't "nullary logic" a contradiction?
The term refers to logic on empty sets.
For example, we can define an operator "sum" that takes a set of integers and returns the "grand total" found by adding all the integers together. (This is called a "fold" or a "reduction" on addition.) What is the sum of the set of integers {1, 2, 3}? It is 6. What is the sum of the empty set of integers? It is 0.
Cool, eh?
The fold of multiply over the empty set is 1. The fold of OR over the empty set of booleans is false. The fold of AND over the empty set of booleans is true.
(The last one is why I take the position that Bob and Mary's are all the same color.)
Marshall Received on Sun Feb 29 2004 - 19:13:20 CET