From 5d4724c7a3303b94b9a9dc2f723c8e75d0963c86 Mon Sep 17 00:00:00 2001
From: ederc <ederc@mathematik.uni-kl.de>
Date: Wed, 11 Dec 2024 10:46:06 +0100
Subject: [PATCH 1/3] adds modStd functionality

---
 src/ideal/ideal.jl | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/ideal/ideal.jl b/src/ideal/ideal.jl
index e2e8e15b0..2994b836c 100644
--- a/src/ideal/ideal.jl
+++ b/src/ideal/ideal.jl
@@ -675,6 +675,30 @@ function std(I::sideal{S}; complete_reduction::Bool=false) where S <: SPolyUnion
    return sideal{S}(R, ptr, true, I.isTwoSided)
 end
 
+
+@doc raw"""
+    modStd(I::sideal{S}; nr_cores::Int=1, exact::Bool=false) where S <: SPolyUnion
+
+Compute a Groebner basis for the ideal $I$ over $QQ$ with multi-modular methods.
+The algorithm computes `nr_cores` modular Groebner basis in parallel. If `exact` is `true`,
+`I` is homogeneous or the monomial ordering is local the resulting Groebner basis over `QQ`
+for `I` is ensured to be correct.
+"""
+function modStd(I::sideal{S}; nr_cores::Int=1, exact::Bool=false) where S <: SPolyUnion
+   R = base_ring(I)
+   exactness = exact == false ? 0 : 1
+   ncores = nr_cores > 0 ? nr_cores : 1
+   if base_ring(R) == QQ
+      ncores_old = LibResources.getcores()
+      LibResources.setcores(ncores)
+      G = LibModstd.modStd(I, exactness)
+      LibResources.setcores(ncores_old)
+      return G
+   else
+      error("modStd is only available over QQ.")
+   end
+end
+
 @doc raw"""
     std_with_HC(I::sideal{{spoly{T}}, HC::spoly{T}) where T <: Nemo.FieldElem
 

From b8ecbc27613d18ad5027a9121bc5bd4945672b6f Mon Sep 17 00:00:00 2001
From: ederc <ederc@mathematik.uni-kl.de>
Date: Wed, 11 Dec 2024 10:48:06 +0100
Subject: [PATCH 2/3] adds modStd call

---
 src/ideal/ideal.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ideal/ideal.jl b/src/ideal/ideal.jl
index 2994b836c..1b2716187 100644
--- a/src/ideal/ideal.jl
+++ b/src/ideal/ideal.jl
@@ -1,7 +1,7 @@
 export sideal, IdealSet, syz, lead, normalize!, is_constant, is_zerodim, fglm,
        fres, dimension, highcorner, jet, kbase, minimal_generating_set,
        independent_sets, maximal_independent_set, mres, mres_with_map,
-       number_of_generators, ngens, nres, sres,
+       modStd, number_of_generators, ngens, nres, sres,
        intersection, homogenize_ideal, homogenize_ideal_with_weights,
        quotient, reduce, eliminate, kernel, equal, contains, is_var_generated,
        saturation, saturation2, satstd, slimgb, std, std_with_HC,

From b0b5ab09ef28b60cc57b6427107ddf1643e21ac2 Mon Sep 17 00:00:00 2001
From: ederc <ederc@mathematik.uni-kl.de>
Date: Wed, 11 Dec 2024 10:48:19 +0100
Subject: [PATCH 3/3] adds test for modStd

---
 test/ideal/sideal-test.jl | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/test/ideal/sideal-test.jl b/test/ideal/sideal-test.jl
index 3721bcf1c..c875bbb36 100644
--- a/test/ideal/sideal-test.jl
+++ b/test/ideal/sideal-test.jl
@@ -297,6 +297,18 @@ end
    @test equal(I, Ideal(R, x^2, y))
 end
 
+@testset "sideal.modstd" begin
+   R, (x, y) = polynomial_ring(QQ, ["x", "y"])
+   I = Ideal(R, x^2 + x*y + 1, 2*x*y^2 + 3)
+   H = Ideal(R, y^2 - 3//2*x - 3//2*y, x^2 + x*y + 1)
+   G = modStd(I)
+   @test equal(G, H)
+   G = modStd(I, exact=true)
+   @test equal(G, H)
+   G = modStd(I, nr_cores=2)
+   @test equal(G, H)
+end
+
 @testset "sideal.intersection" begin
    R, (x, y) = polynomial_ring(QQ, ["x", "y"])