This function is provided by the package
LLLBases.
The first n-1 columns of the matrix z form a basis of the kernel of the n integers of the list s, and the dot product of the last column of z and s is the gcd g.
The method used is described in the paper:
Havas, Majewski, Matthews,
Extended GCD and Hermite Normal Form Algorithms via Lattice Basis Reduction, Experimental Mathematics 7:2 p. 125 (1998).
For an example,
i1 : s = apply(5,i->372*(random 1000000))
o1 = {7451904, 371210988, 148215588, 260679744, 86537616}
o1 : List
|
i2 : (g,z) = gcdLLL s
o2 = (372, | 17 -11 -20 -17 -13 |)
| -12 -1 -9 -22 -4 |
| 4 3 -21 46 13 |
| 13 8 24 4 1 |
| 4 -24 4 5 -7 |
o2 : Sequence
|
i3 : matrix{s} * z
o3 = | 0 0 0 0 372 |
1 5
o3 : Matrix ZZ <--- ZZ
|