[118983] in Cypherpunks
Re: Square roots of nonsingular binary matrices (fwd)
daemon@ATHENA.MIT.EDU (Jonathan Stafford)
Tue Oct 12 01:22:28 1999
Date: Tue, 12 Oct 1999 01:09:13 -0400 (EDT)
From: Jonathan Stafford <jestaff2@unity.ncsu.edu>
To: cypherpunks@einstein.ssz.com
In-Reply-To: <199910120333.WAA19888@einstein.ssz.com>
Message-ID: <Pine.SOL.4.05.9910120102450.19508-100000@eos00du.eos.ncsu.edu>
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Reply-To: Jonathan Stafford <jestaff2@unity.ncsu.edu>
On Mon, 11 Oct 1999, Jim Choate, confused by odd binary math, wrote:
>
>
> ----- Forwarded message from bill payne -----
>
> Date: Mon, 11 Oct 1999 20:42:55 -0600
> >From: bill payne <billp@nmol.com>
> Subject: CDR: Square roots of nonsingular binary matrices
>
> ...
>
> Let’s try it.
>
> 011 011 0 1 0
> 111 111 = 0 0 1
> 101 101 1 1 0
>
> Mission accomplished.
>
> ...
>
> ----- End of forwarded message from bill payne -----
>
> There's something wrong with your math...
>
> 0 1 1 0 1 1 2 1 2
> 1 1 1 1 1 1 = 2 2 3
> 1 0 1 1 0 1 1 1 2
You missed the subject line...
> Subject: CDR: Square roots of nonsingular binary matrices
^^^^^^
This is binary, not normal math. And not even normal binary matrices.
Usually, at least in the class I took, you use OR and not XOR:
011 011 abc
111 111 = def =
101 101 ghi
a = (0 & 0) ^ (1 & 1) ^ (1 & 1) = 0 ^ 1 ^ 1 = 0
b = (0 & 1) ^ (1 & 1) ^ (1 & 0) = 0 ^ 1 ^ 0 = 1
...
The remainder is left as practice for the reader.
Jonathan
--
This message is meaningless and subject to change.
