HELP FOR: The CREP dataformat for unitforms

SYNOPSIS:

• A unit form q is a map
  Zⁿ ---> Z,

  x --->

  xi2 +

  ai,jxixj

  where Z denotes the ring of integers and a_i,j are integers.

• A unit form q is represented by its symmetric integer-coefficient matrix Q, i.e. a matrix Q such that q(x) = 1/2 x^T Q x

EXAMPLES:

> with(linalg);

> Q:=matrix(3,3,[2,1,0,1,2,-1,0,-1,2]);

> x:=vector(3);

> print(x);

> 1/2*innerprod(x,Q,x);