Function: qfisominit
Section: linear_algebra
C-Name: qfisominit0
Prototype: GDGDG
Help: qfisominit(G,{fl},{m}): G being a square and symmetric matrix representing an
 integral positive definite quadratic form, this function returns a structure
 allowing to compute isomorphisms between G and other quadratic form faster.
Doc:
 $G$ being a square and symmetric matrix with integer entries representing a
 positive definite quadratic form, return an \kbd{isom} structure allowing to
 compute isomorphisms between $G$ and other quadratic forms faster.

 The interface of this function is experimental and will likely change in future
 release.

 If present, the optional parameter \var{fl} must be a \typ{VEC} with two
 components. It allows to specify the invariants used, which can make the
 computation faster or slower. The components are

 \item \kbd{fl[1]} Depth of scalar product combination to use.

 \item \kbd{fl[2]} Maximum level of Bacher polynomials to use.

 If present, $m$ must be the set of vectors of norm up to the maximal of the
 diagonal entry of $G$, either as a matrix or as given by \kbd{qfminim}.
 Otherwise this function computes the minimal vectors so it become very
 lengthy as the dimension of $G$ grows.
Variant: Also available is
 \fun{GEN}{qfisominit}{GEN F, GEN fl}
 where $F$ is a vector of \kbd{zm}.
