# Re: A Simple Notation

Date: Thu, 05 Jul 2007 10:18:33 -0300

Message-ID: <468cef93$0$4340$9a566e8b_at_news.aliant.net>

David Cressey wrote:

> In Boolean algebra, you could, if you wanted to, express everything by just

*> using brackets, as follows:
**>
**> [A B] means NOT (A AND B)
**>
**> This notation can be extended to 3 or more operands, as follows:
**>
**> [A B C] means NOT (A AND B AND C)
**>
**> "AND" is associative, so there's no confusion.
**>
**> You can reduce the notation to 1 operand as follows:
**>
**> [A] means NOT (A)
**>
**> And to zero operands as follows:
**>
**> [] means TRUE
**> [[]] means FALSE
**>
**> You can build up everything else from there. For example,
**>
**> [[A B]] = A AND B
**> [[A] [B]] = A OR B
**>
**> Now my question is, can you do the corresponding thing in the RA, using
**> <NOT> and <AND>? I don't see why not.
**>
**> So you would get (for example)
**>
**> [[A B]] = A <AND> B
**> [[A] [B]] = A <OR> B
**>
**> As written text, this notation is rather unwieldy, but you can represent it
**> fairly tightly in internal data structures. And its simplicity does make
**> some things easier.
*

Then again, perhaps you refer to the same thing with <AND> and <OR> in which case, I simply agree that using [A B] to mean <NOT>(A <AND> B) achieves something similar. Received on Thu Jul 05 2007 - 15:18:33 CEST