Bug in GeneratorsOfAffineSemigroup when using NormalizInterface

[coneill-math]

When using NormalizInterface, the function GeneratorsOfAffineSemigroup fails for some affine semigroups. See the output below.

gap> LoadPackage("num");
----------------------------------------------------------------
Loading  NumericalSgps 1.4.0
For help, type: ?NumericalSgps: 
To gain profit from other packages, please refer to chapter
'External Packages' in the manual, or type: ?NumSgpsUse 
----------------------------------------------------------------
true
gap> NumSgpsUseNormaliz();
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Loading NormalizInterface 1.4.1 (GAP wrapper for Normaliz)
(Normaliz version is 3.10.2)
by Sebastian Gutsche (gutsche@mathematik.uni-siegen.de),
   Max Horn (https://www.quendi.de/math), and
   Christof Söger (csoeger@uos.de).
maintained by:
   Max Horn (https://www.quendi.de/math).
Homepage: https://gap-packages.github.io/NormalizInterface
Report issues at https://github.com/gap-packages/NormalizInterface/issues
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
true
gap> S:=[-2 .. 2];
[ -2 .. 2 ]
gap> a:=AffineSemigroupByEquations([[S],[]]);
<Affine semigroup>
gap> gens:=GeneratorsOfAffineSemigroup(a);
Error, Element 2 of the input list must be an integer matrix in
  _NmzCone( opts_list ) at /home/sage/sage/local/lib/gap/pkg/NormalizInterface-1.4.1/lib/normaliz.gi:111 called from 
NmzCone( [ "equations", matfree ] ) at /home/sage/sage/local/lib/gap/pkg/NumericalSgps-1.4.0/gap/affine-extra-ni.gi:80 called from
HilbertBasisOfSystemOfHomogeneousEquations( eq[1], eq[2] ) at /home/sage/sage/local/lib/gap/pkg/NumericalSgps-1.4.0/gap/affine-def.gi:68 called from
<function "Generators Computes a set of generators of the affine semigroup">( <arguments> )
 called from read-eval loop at *stdin*:5
gap> S:=[-2,-1,0,1,2];
[ -2, -1, 0, 1, 2 ]
gap> a:=AffineSemigroupByEquations([[S],[]]);
<Affine semigroup>
gap> gens:=GeneratorsOfAffineSemigroup(a);
[ [ 0, 0, 1, 0, 0 ], [ 0, 1, 0, 1, 0 ], [ 0, 2, 0, 0, 1 ], [ 1, 0, 0, 0, 1 ], [ 1, 0, 0, 2, 0 ] ]

The problem seems to be when .. is used to make the list.

[pedritomelenas]

Thanks, I narrowed it down to gap-packages/NormalizInterface#121
A workaround it shown there, and for your example you could use AffineSemigroupByEquations([[List(S,x->x)],[]]).