Re: Inverse????
- To: mathgroup at smc.vnet.net
- Subject: [mg5499] Re: [mg5477] Inverse????
- From: Daniel Lichtblau <danl>
- Date: Sat, 14 Dec 1996 19:26:04 -0500
- Organization: wolfram.com
- Sender: owner-wri-mathgroup at wolfram.com
Hou-shou Chen wrote:
>
> A matrix a={{0,0,1},{0,0,1},{1,1,1}} which is singular in Z_2, but
> Inverse commands gives the "result":
>
> Inverse[a,Modulus->2]=
> {{0, 1, 1}, {1, 1, 0}, {1, 0, 0}}.
>
> Is anything wrong ?
>
> Houshou
Yes. It was a bug. Fixed in version 3.0.
In[5]:= a={{0,0,1},{0,0,1},{1,1,1}};
In[6]:= Det[a, Modulus->2]
Out[6]= 0
In[7]:= Inverse[a,Modulus->2]
Inverse::sing: Matrix {{0, 0, 1}, {0, 0, 1}, {1, 1, 1}} is singular.
Out[7]= Inverse[{{0, 0, 1}, {0, 0, 1}, {1, 1, 1}}, Modulus -> 2]
Daniel Lichtblau
Wolfram Research
danl at wolfram.com