Merge pull request #3659 from fingolfin/mh/_normal_form_singular

oscar-system · May 3, 2024 · 7f5cfd2 · 7f5cfd2
2 parents 00786b1 + dacdfae
commit 7f5cfd2
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/src/Rings/groebner.jl b/src/Rings/groebner.jl
@@ -1157,11 +1157,13 @@ julia> Oscar._normal_form_singular(A, J, default_ordering(base_ring(J)))
 ```
 """
 function _normal_form_singular(A::Vector{T}, J::MPolyIdeal, ordering::MonomialOrdering) where { T <: MPolyRingElem }
-  SR = singular_poly_ring(base_ring(J), ordering)
-  IS = Singular.Ideal(SR, [SR(x) for x in A])
   GS = singular_groebner_generators(J, ordering)
-  K  = ideal(base_ring(J), reduce(IS, GS))
-  return [J.gens.Ox(x) for x = gens(K.gens.S)]
+  SR = base_ring(GS)
+  tmp = map(SR, A)
+  IS = Singular.Ideal(SR, tmp)
+  K = reduce(IS, GS)
+  OR = base_ring(J)
+  return map(OR, gens(K))
 end
 
 @doc raw"""

diff --git a/test/Rings/groebner.jl b/test/Rings/groebner.jl
@@ -122,6 +122,13 @@
     @test_throws ArgumentError standard_basis_highest_corner(I)
 end
 
+@testset "normal form graded" begin
+    R, (a, b, c) = graded_polynomial_ring(QQ, ["a", "b", "c"])
+    I = ideal([a^2+b^2, c^3])
+    # verify normal form of inhomogeneous polynomial work
+    @test normal_form(a^2+b, I) == -b^2+b
+end
+
 @testset "groebner leading ideal" begin
    R, (t, x, y, z) = polynomial_ring(QQ, ["t", "x", "y", "z"])