Look up: Zero-X

1. zero matrix
   (from the article `matrix`) A matrix O with all its elements 0 is called a zero matrix. A square matrix A with 1s on the main diagonal (upper left to lower right) and 0s ...
   Found on http://www.britannica.com/eb/a-z/z/6
   
   
2. Zero matrix
   In mathematics, particularly linear algebra, a `zero matrix` or `null matrix` is a matrix with all its entries being zero. Some examples of zero matrices are :<math> 0_{1,1} = egin{bmatrix} 0 end{bmatrix} , 0_{2,2} = egin{bmatrix} 0 & 0 \ 0 & 0 end{bmatrix} , 0_{2,3} = egin{bmatrix} 0 ...
   Found on http://en.wikipedia.org/wiki/Zero_matrix
   
   
3. Zero X
   The `Zero X` is an electric motorcycle manufactured by Zero Motorcycles. Specifications: The wheels are driven by hardened steel 420 chain and direct drive gearing. Braking is performed by six-piston calipers per axle, with front rotor. It includes rear rim with rear tire and front tire. Standard ba...
   Found on http://en.wikipedia.org/wiki/Zero_X
   
   
4. Zero-X
   The `Zero-X` (spelling variants include: "Zero X" or "Zero - X") is a fictitious Earth spacecraft that appeared in two of Gerry and Sylvia Anderson`s Supermarionation productions. Although publicity material for the various Supermarionation series, and the
   Found on http://en.wikipedia.org/wiki/Zero-X