Function: matkerint
Section: linear_algebra
C-Name: matkerint0
Prototype: GD0,L,
Help: matkerint(x,{flag=0}): LLL-reduced Z-basis of the kernel of the matrix
 x with integral entries. flag is optional, and may be set to 0: default,
 uses LLL, 1: uses matrixqz (much slower).
Doc: gives an \idx{LLL}-reduced $\Z$-basis
 for the lattice equal to the kernel of the matrix $x$ as columns of the
 matrix $x$ with integer entries (rational entries are not permitted).

 If $\fl=0$, uses an integer LLL algorithm.

 If $\fl=1$, uses $\kbd{matrixqz}(x,-2)$. Many orders of magnitude slower
 than the default: never use this.

Variant: See also \fun{GEN}{kerint}{GEN x} ($\fl=0$), which is a trivial
 wrapper around
 \bprog
 ZM_lll(ZM_lll(x, 0.99, LLL_KER), 0.99, LLL_INPLACE);
 @eprog\noindent Remove the outermost \kbd{ZM\_lll} if LLL-reduction is not
 desired (saves time).
