Trac #25993: Upgrade Singular

Tarball: `see checksums.ini` on the branch

Use `make SAGE_SPKG="sage-spkg -o" singular-clean sagelib-clean build`
to automatically download and install.

"Critical" because it enables supporting newer versions of FLINT.

We use the Singular development branch (`spielwiese`) + PR
Singular/Singular#1058 in order to build
documentation. The tarball is made from
https://github.com/mkoeppe/Singular/tree/Release-4-2-0-p1%2Bsage

URL: https://trac.sagemath.org/25993
Reported by: jdemeyer
Ticket author(s): Antonio Rojas, Markus Wageringel, Matthias Koeppe
Reviewer(s): Matthias Koeppe, Dima Pasechnik

build/pkgs/pysingular/checksums.ini

@@ -1,4 +1,5 @@
 tarball=PySingular-VERSION.tar.gz
-sha1=760ccdd20c869c5a874100df02e9031fc0c6157a
-md5=f2698b633915199fc27c9772e4688754
-cksum=1655432975
+sha1=c8d4bbe4552490aac37afe6d87a2cd3a7b445a7e
+md5=84a8639d33a5b03637a7ca3ea322b085
+cksum=822399760
+upstream_url=https://pypi.io/packages/source/p/pysingular/PySingular-VERSION.tar.gz

build/pkgs/pysingular/package-version.txt

@@ -1 +1 @@
-0.9.5
+0.9.7

build/pkgs/singular/SPKG.rst

@@ -35,7 +35,8 @@ Dependencies
 Special Update/Build Instructions
 ---------------------------------
 
-See spkg-src to create the source tarball.
+The current upstream tarball is made from the branch at
+https://github.com/mkoeppe/Singular/tree/Release-4-2-0-p1%2Bsage
 
 Other notes:
 

build/pkgs/singular/checksums.ini

@@ -1,4 +1,5 @@
 tarball=singular-VERSION.tar.gz
-sha1=5c6b6c3d2b5ebaca164967eec67e59ebb4e6142f
-md5=cb50d64ab1b2b49a0c3f519e5c87639e
-cksum=4294037094
+sha1=eeb0b250e481e710daea45c2f78ccff9b84e6f15
+md5=88c4500c2d6ac3eb9b112111fc9404ad
+cksum=3131197750
+upstream_url=https://trac.sagemath.org/raw-attachment/ticket/25993/singular-VERSION.tar.gz

build/pkgs/singular/package-version.txt

@@ -1 +1 @@
-4.1.1p2.p0
+4.2.0p1+2021-03-13+sage

build/pkgs/singular/patches/configure-no-ntl-header-check.patch

@@ -49,30 +49,4 @@ index db6423d..c0a2260 100755
 +## fi
  done
 
- if test "x$ntl_found" = "xyes" ; then
-diff --git a/libpolys/configure b/libpolys/configure
-index 41b0928..9a4b9f5 100755
---- a/libpolys/configure
-+++ b/libpolys/configure
-@@ -20660,7 +20660,7 @@ fi
-
- for NTL_HOME in ${NTL_HOME_PATH}
-  do
--if test -r "$NTL_HOME/include/NTL/ZZ.h"; then
-+## if test -r "$NTL_HOME/include/NTL/ZZ.h"; then
-
- 	if test "x$NTL_HOME" != "x/usr"; then
- 		NTL_CPPFLAGS="-I${NTL_HOME}/include"
-@@ -20731,9 +20731,9 @@ else
- fi
- rm -f core conftest.err conftest.$ac_objext \
-     conftest$ac_exeext conftest.$ac_ext
--else
--	ntl_found="no"
--fi
-+## else
-+## 	ntl_found="no"
-+## fi
- done
-
  if test "x$ntl_found" = "xyes" ; then

build/pkgs/singular/spkg-install.in

@@ -58,6 +58,11 @@ remove_old_version()
 
 config()
 {
+    if [ "$UNAME" = "CYGWIN" ]; then
+        # from Hans Schoenemann - https://github.com/Singular/Singular/issues/1017
+        SINGULAR_CONFIGURE="$SINGULAR_CONFIGURE --disable-p-procs-dynamic --enable-p-procs-static --with-builtinmodules=gfanlib,gitfan,interval,loctriv,partialgb,syzextra,customstd,cohomo,subsets,freealgebra,systhreads --disable-cf-inline --disable-Order-module --disable-bigintm-module --disable-pyobject-module"
+    fi
+
     # configure notes (dates from Singular 3.x, maybe outdated for 4.x):
     # 1) We really need to add --exec-prefix and --bindir as Singular
     #    uses some weird defaults.
@@ -76,15 +81,28 @@ config()
                   --disable-doc \
                   --disable-polymake \
                   --without-python \
+                  --without-pythonmodule \
                   --disable-python \
+                  --disable-python_module \
+                  --disable-python-module \
+                  --disable-static \
                   $SINGULAR_CONFIGURE
 }
 
 
 build_singular()
 {
-    sdh_make
+    for subdir in omalloc gfanlib resources omalloc factory libpolys gfanlib IntegerProgramming; do
+        sdh_make -w -C $subdir
+    done
+    # Possible parallelization bugs in subdirectory Singular
+    sdh_make -j1
     sdh_make_install
+
+    # Singular tarballs made using "make dist" do not contain built documentation.
+    if [ ! -e doc/doc.tbz2 ]; then
+        (cd doc && make singular.hlp && sdh_install singular.hlp "$SAGE_SHARE/info/") || sdh_die "Building documentation failed"
+    fi
 }
 
 

src/doc/en/constructions/algebraic_geometry.rst

@@ -139,7 +139,7 @@ Other methods
 
        sage: singular.lib("brnoeth.lib")
        sage: s = singular.ring(2,'(x,y)','lp')
-       sage: I = singular.ideal('[x^4+x, y^4+y]')
+       sage: I = singular.ideal('x^4+x', 'y^4+y')
        sage: L = singular.closed_points(I)
        sage: # Here you have all the points :
        sage: L       # random
@@ -329,7 +329,7 @@ Singular itself to help an understanding of how the wrapper works.
        sage: X = Curve(f); pts = X.rational_points()
        sage: D = X.divisor([ (3, pts[0]), (-1,pts[1]), (10, pts[5]) ])
        sage: X.riemann_roch_basis(D)
-       [(-x - 2*y)/(-2*x - 2*y), (-x + z)/(x + y)]
+       [(-2*x + y)/(x + y), (-x + z)/(x + y)]
 
 -  Using Singular's ``BrillNoether`` command (for details see the section
    Brill-Noether in the Singular online documentation

src/sage/algebras/free_algebra.py

@@ -39,7 +39,15 @@
     Free Associative Unital Algebra on 3 generators (x, y, z) over Rational Field
     sage: I = F*[x*y+y*z,x^2+x*y-y*x-y^2]*F
     sage: I.groebner_basis(degbound=4)
-    Twosided Ideal (y*z*y*y - y*z*y*z + y*z*z*y - y*z*z*z, y*z*y*x + y*z*y*z + y*z*z*x + y*z*z*z, y*y*z*y - y*y*z*z + y*z*z*y - y*z*z*z, y*y*z*x + y*y*z*z + y*z*z*x + y*z*z*z, y*y*y - y*y*z + y*z*y - y*z*z, y*y*x + y*y*z + y*z*x + y*z*z, x*y + y*z, x*x - y*x - y*y - y*z) of Free Associative Unital Algebra on 3 generators (x, y, z) over Rational Field
+    Twosided Ideal (x*y + y*z,
+        x*x - y*x - y*y - y*z,
+        y*y*y - y*y*z + y*z*y - y*z*z,
+        y*y*x + y*y*z + y*z*x + y*z*z,
+        y*y*z*y - y*y*z*z + y*z*z*y - y*z*z*z,
+        y*z*y*y - y*z*y*z + y*z*z*y - y*z*z*z,
+        y*y*z*x + y*y*z*z + y*z*z*x + y*z*z*z,
+        y*z*y*x + y*z*y*z + y*z*z*x + y*z*z*z) of Free Associative Unital
+        Algebra on 3 generators (x, y, z) over Rational Field
     sage: y*z*y*y*z*z + 2*y*z*y*z*z*x + y*z*y*z*z*z - y*z*z*y*z*x + y*z*z*z*z*x in I
     True
 
@@ -232,7 +240,7 @@ class FreeAlgebraFactory(UniqueFactory):
         a*b^2*c^3
     """
     def create_key(self, base_ring, arg1=None, arg2=None,
-            sparse=None, order='degrevlex',
+            sparse=None, order=None,
             names=None, name=None,
             implementation=None, degrees=None):
         """
@@ -263,6 +271,8 @@ def create_key(self, base_ring, arg1=None, arg2=None,
             return tuple(degrees),base_ring
         # test if we can use libSingular/letterplace
         if implementation == "letterplace":
+            if order is None:
+                order = 'degrevlex' if degrees is None else 'deglex'
             args = [arg for arg in (arg1, arg2) if arg is not None]
             kwds = dict(sparse=sparse, order=order, implementation="singular")
             if name is not None:
@@ -273,7 +283,7 @@ def create_key(self, base_ring, arg1=None, arg2=None,
             if degrees is None:
                 return (PolRing,)
             from sage.all import TermOrder
-            T = PolRing.term_order() + TermOrder('lex',1)
+            T = TermOrder(PolRing.term_order(), PolRing.ngens() + 1)
             varnames = list(PolRing.variable_names())
             newname = 'x'
             while newname in varnames:

src/sage/algebras/letterplace/free_algebra_element_letterplace.pyx

@@ -17,6 +17,7 @@ AUTHOR:
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
+from sage.groups.perm_gps.all import CyclicPermutationGroup
 from sage.libs.singular.function import lib, singular_function
 from sage.misc.repr import repr_lincomb
 from sage.rings.polynomial.multi_polynomial_ideal import MPolynomialIdeal
@@ -25,7 +26,6 @@ from cpython.object cimport PyObject_RichCompare
 # Define some singular functions
 lib("freegb.lib")
 poly_reduce = singular_function("NF")
-singular_system=singular_function("system")
 
 #####################
 # Free algebra elements
@@ -445,9 +445,10 @@ cdef class FreeAlgebraElement_letterplace(AlgebraElement):
         cdef int i
         if P.monomial_divides(s_poly,p_poly):
             return True
+        realngens = A._commutative_ring.ngens()
+        CG = CyclicPermutationGroup(P.ngens())
         for i from 0 <= i < p_d-s_d:
-            s_poly = singular_system("stest",s_poly,1,
-                                     A._degbound,A.__ngens,ring=P)
+            s_poly = s_poly * CG[realngens]
             if P.monomial_divides(s_poly,p_poly):
                 return True
         return False
@@ -601,7 +602,9 @@ cdef class FreeAlgebraElement_letterplace(AlgebraElement):
         # we must put the polynomials into the same ring
         left._poly = A._current_ring(left._poly)
         right._poly = A._current_ring(right._poly)
-        rshift = singular_system("stest",right._poly,left._poly.degree(),A._degbound,A.__ngens, ring=A._current_ring)
+        realngens = A._commutative_ring.ngens()
+        CG = CyclicPermutationGroup(A._current_ring.ngens())
+        rshift = right._poly * CG[left._poly.degree() * realngens]
         return FreeAlgebraElement_letterplace(A,left._poly*rshift, check=False)
 
     def __pow__(FreeAlgebraElement_letterplace self, int n, k):
@@ -627,10 +630,11 @@ cdef class FreeAlgebraElement_letterplace(AlgebraElement):
         self._poly = A._current_ring(self._poly)
         cdef int d = self._poly.degree()
         q = p = self._poly
+        realngens = A._commutative_ring.ngens()
         cdef int i
+        CG = CyclicPermutationGroup(A._current_ring.ngens())
         for i from 0<i<n:
-            q = singular_system("stest",q,d,A._degbound,A.__ngens,
-                                     ring=A._current_ring)
+            q = q * CG[d * realngens]
             p *= q
         return FreeAlgebraElement_letterplace(A, p, check=False)
 

src/sage/algebras/letterplace/free_algebra_letterplace.pxd

@@ -13,8 +13,15 @@ from sage.rings.ring cimport Algebra
 from sage.structure.element cimport AlgebraElement, ModuleElement, RingElement, Element
 from sage.rings.polynomial.multi_polynomial_libsingular cimport MPolynomialRing_libsingular, MPolynomial_libsingular
 from sage.algebras.letterplace.free_algebra_element_letterplace cimport FreeAlgebraElement_letterplace
+from sage.libs.singular.decl cimport ring
 
 
+cdef class FreeAlgebra_letterplace_libsingular():
+    cdef ring* _lp_ring
+    cdef MPolynomialRing_libsingular _commutative_ring
+    cdef MPolynomialRing_libsingular _lp_ring_internal
+    cdef object __ngens
+
 cdef class FreeAlgebra_letterplace(Algebra):
     cdef MPolynomialRing_libsingular _commutative_ring
     cdef MPolynomialRing_libsingular _current_ring