diff --git a/src/sage/algebras/orlik_solomon.py b/src/sage/algebras/orlik_solomon.py index 113bb29418f..f1b46ca4c65 100644 --- a/src/sage/algebras/orlik_solomon.py +++ b/src/sage/algebras/orlik_solomon.py @@ -192,7 +192,7 @@ def one_basis(self): sage: M = matroids.Wheel(3) sage: OS = M.orlik_solomon_algebra(QQ) - sage: OS.one_basis() == frozenset([]) + sage: OS.one_basis() == frozenset() True """ return frozenset({}) @@ -347,7 +347,7 @@ def subset_image(self, S): [[(1, 2), (1, 4), (2, 3), (3, 4)], [(3, 5), (3, 6), (5, 6)]] sage: OSMG = MG.orlik_solomon_algebra(QQ, ordering=s) - sage: OSMG.subset_image(frozenset([])) + sage: OSMG.subset_image(frozenset()) OS{} sage: OSMG.subset_image(frozenset([(1,2),(3,4),(1,4),(2,3)])) 0 @@ -375,7 +375,7 @@ def subset_image(self, S): [0, 3, 5], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3, 5], [2, 3], [4, 5]] sage: OSMG = MG.orlik_solomon_algebra(QQ) - sage: OSMG.subset_image(frozenset([])) + sage: OSMG.subset_image(frozenset()) OS{} sage: OSMG.subset_image(frozenset([1, 2, 3])) 0 @@ -394,7 +394,7 @@ def subset_image(self, S): sage: sorted([sorted(c) for c in MG.circuits()]) [[0, 1], [2, 3, 4]] sage: OSMG = MG.orlik_solomon_algebra(QQ) - sage: OSMG.subset_image(frozenset([])) + sage: OSMG.subset_image(frozenset()) OS{} sage: OSMG.subset_image(frozenset([1, 3, 4])) -OS{0, 2, 3} + OS{0, 2, 4} diff --git a/src/sage/algebras/orlik_terao.py b/src/sage/algebras/orlik_terao.py index 26b3c49b443..b039e7bef3f 100644 --- a/src/sage/algebras/orlik_terao.py +++ b/src/sage/algebras/orlik_terao.py @@ -242,7 +242,7 @@ def one_basis(self): sage: M = matroids.Wheel(3) sage: OT = M.orlik_terao_algebra(QQ) - sage: OT.one_basis() == frozenset([]) + sage: OT.one_basis() == frozenset() True """ return frozenset({}) @@ -391,7 +391,7 @@ def subset_image(self, S): [[(1, 2), (1, 4), (2, 3), (3, 4)], [(3, 5), (3, 6), (5, 6)]] sage: OT = M.orlik_terao_algebra(QQ, ordering=s) - sage: OT.subset_image(frozenset([])) + sage: OT.subset_image(frozenset()) OT{} sage: OT.subset_image(frozenset([(1,2),(3,4),(1,4),(2,3)])) 0 @@ -419,7 +419,7 @@ def subset_image(self, S): [0, 3, 5], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3, 5], [2, 3], [4, 5]] sage: OT = M.orlik_terao_algebra() - sage: OT.subset_image(frozenset([])) + sage: OT.subset_image(frozenset()) OT{} sage: OT.subset_image(frozenset([1, 2, 3])) 0 @@ -438,7 +438,7 @@ def subset_image(self, S): sage: sorted([sorted(c) for c in M.circuits()]) [[0, 1], [2, 3, 4]] sage: OT = M.orlik_terao_algebra(QQ) - sage: OT.subset_image(frozenset([])) + sage: OT.subset_image(frozenset()) OT{} sage: OT.subset_image(frozenset([1, 3, 4])) -OT{0, 2, 3} + OT{0, 2, 4} diff --git a/src/sage/calculus/desolvers.py b/src/sage/calculus/desolvers.py index 6a8d8fbe2bb..e959c22f234 100644 --- a/src/sage/calculus/desolvers.py +++ b/src/sage/calculus/desolvers.py @@ -913,7 +913,7 @@ def desolve_system(des, vars, ics=None, ivar=None, algorithm='maxima'): if len(des) == 1 and algorithm == "maxima": return desolve_laplace(des[0], vars[0], ics=ics, ivar=ivar) - ivars = set([]) + ivars = set() for i, de in enumerate(des): if not (isinstance(de, Expression) and de.is_relational()): des[i] = de == 0 @@ -1440,11 +1440,10 @@ def desolve_system_rk4(des, vars, ics=None, ivar=None, end_points=None, step=0.1 - Robert Marik (10-2009) """ - if ics is None: raise ValueError("No initial conditions, specify with ics=[x0,y01,y02,...].") - ivars = set([]) + ivars = set() for de in des: ivars = ivars.union(set(de.variables())) diff --git a/src/sage/combinat/root_system/pieri_factors.py b/src/sage/combinat/root_system/pieri_factors.py index c1f2ba8afd3..e903042dc63 100644 --- a/src/sage/combinat/root_system/pieri_factors.py +++ b/src/sage/combinat/root_system/pieri_factors.py @@ -519,7 +519,7 @@ class PieriFactors_type_A_affine(PieriFactors_affine_type): @staticmethod def __classcall__(cls, W, min_length=0, max_length=infinity, - min_support=frozenset([]), max_support=None): + min_support=frozenset(), max_support=None): r""" TESTS:: diff --git a/src/sage/doctest/util.py b/src/sage/doctest/util.py index a62d48cfa19..b78dd838e18 100644 --- a/src/sage/doctest/util.py +++ b/src/sage/doctest/util.py @@ -606,7 +606,7 @@ def make_recording_dict(D, st, gt): EXAMPLES:: sage: from sage.doctest.util import make_recording_dict - sage: D = make_recording_dict({'a':4,'d':42},set([]),set(['not_here'])) + sage: D = make_recording_dict({'a':4,'d':42},set(),set(['not_here'])) sage: sorted(D.items()) [('a', 4), ('d', 42)] sage: D.got diff --git a/src/sage/geometry/fan.py b/src/sage/geometry/fan.py index fc004dd88ac..7af1fa122ee 100644 --- a/src/sage/geometry/fan.py +++ b/src/sage/geometry/fan.py @@ -636,7 +636,7 @@ def result(): (len(cones), len(generating_cones))) elif discard_faces: cones = _discard_faces(cones) - ray_set = set([]) + ray_set = set() for cone in cones: ray_set.update(cone.rays()) if rays: # Preserve the initial order of rays, if they were given diff --git a/src/sage/geometry/hasse_diagram.py b/src/sage/geometry/hasse_diagram.py index 74a30abed6d..1b95deb7382 100644 --- a/src/sage/geometry/hasse_diagram.py +++ b/src/sage/geometry/hasse_diagram.py @@ -146,7 +146,7 @@ def default_face_constructor(atoms, coatoms, **kwds): atoms = atoms.intersection(coatom_to_atoms[coatom]) H[atom] = (atoms, coatoms) # 8: compute the set G of minimal sets in H - minimals = set([]) + minimals = set() while candidates: candidate = candidates.pop() atoms = H[candidate][0] diff --git a/src/sage/geometry/hyperplane_arrangement/arrangement.py b/src/sage/geometry/hyperplane_arrangement/arrangement.py index 8517bb36671..854c412fc83 100644 --- a/src/sage/geometry/hyperplane_arrangement/arrangement.py +++ b/src/sage/geometry/hyperplane_arrangement/arrangement.py @@ -2199,7 +2199,7 @@ def poset_of_regions(self, B=None, numbered_labels=True): while R: # Transfer the "next step" to the "current step" curTest = list(nextTest) - nextTest = set([]) + nextTest = set() # we want to test each region that we haven't hit yet for r in R: # Since it's graded, it suffices to look at the regions of the previous rank diff --git a/src/sage/geometry/lattice_polytope.py b/src/sage/geometry/lattice_polytope.py index da030a17966..eb386e3f9a9 100644 --- a/src/sage/geometry/lattice_polytope.py +++ b/src/sage/geometry/lattice_polytope.py @@ -3947,11 +3947,10 @@ def skeleton_points(self, k=1): """ if k >= self.dim(): return list(range(self.npoints())) - skeleton = set([]) + skeleton = set() for face in self.faces(dim=k): skeleton.update(face.ambient_point_indices()) - skeleton = sorted(skeleton) - return skeleton + return sorted(skeleton) def skeleton_show(self, normal=None): r"""Show the graph of one-skeleton of this polytope. diff --git a/src/sage/geometry/polyhedral_complex.py b/src/sage/geometry/polyhedral_complex.py index 768c0cfe82a..9d6b4c84d6e 100644 --- a/src/sage/geometry/polyhedral_complex.py +++ b/src/sage/geometry/polyhedral_complex.py @@ -370,7 +370,7 @@ def cells(self, subcomplex=None) -> dict: for k in range(self._dim, -1, -1): if k in maximal_cells: if k not in cells: - cells[k] = set([]) + cells[k] = set() cells[k].update(maximal_cells[k]) if k in cells: for cell in cells[k]: @@ -382,7 +382,7 @@ def cells(self, subcomplex=None) -> dict: covers[p] = [] covers[p].append(cell) if (k-1) not in cells: - cells[k-1] = set([]) + cells[k-1] = set() cells[k-1].add(p) self._face_poset = Poset(covers) self._cells = cells @@ -1055,7 +1055,7 @@ def is_subcomplex(self, other) -> bool: """ other_cells = other.cells() for (d, stratum) in self.maximal_cells().items(): - if not stratum.issubset(other_cells.get(d, set([]))): + if not stratum.issubset(other_cells.get(d, set())): return False return True @@ -1594,9 +1594,9 @@ def is_convex(self) -> bool: # After making sure that the affine hulls of the cells are the same, # it does not matter that is not full dimensional. boundaries = self.relative_boundary_cells() - vertices = set([]) - rays = set([]) - lines = set([]) + vertices = set() + rays = set() + lines = set() for cell in boundaries: # it suffices to consider only vertices on the boundaries # Note that a line (as polyhedron) has vertex too @@ -2055,7 +2055,7 @@ def add_cell(self, cell): for facet in c.facets(): p = facet.as_polyhedron() if d not in cells: - cells[d] = set([]) + cells[d] = set() if p not in cells[d]: cells[d].add(p) covers[p] = [c] @@ -2358,7 +2358,7 @@ def subdivide(self, make_simplicial=False, if new_rays: raise ValueError("rays/lines cannot be used for subdivision") # bounded version of `fan.subdivide`; not require rational. - vertices = set([]) + vertices = set() if make_simplicial and not self.is_simplicial_complex(): for p in self.maximal_cell_iterator(): for v in p.vertices_list(): @@ -2390,7 +2390,7 @@ def subdivide(self, make_simplicial=False, raise ValueError("new vertices cannot be used for subdivision") # mimic :meth:`~sage.geometry.fan .subdivide` # but here we allow for non-pointed cones, and we subdivide them. - rays_normalized = set([]) + rays_normalized = set() self_rays = [] cones = [] for p in self.maximal_cell_iterator(): diff --git a/src/sage/graphs/generators/families.py b/src/sage/graphs/generators/families.py index 74e7dd01f28..71a146f6b49 100644 --- a/src/sage/graphs/generators/families.py +++ b/src/sage/graphs/generators/families.py @@ -3135,7 +3135,7 @@ def YDeltaTrans(G, v): # for as long as we generate new graphs. P = PetersenGraph() - l = set([]) + l = set() l_new = [P.canonical_label().graph6_string()] while l_new: diff --git a/src/sage/graphs/generators/smallgraphs.py b/src/sage/graphs/generators/smallgraphs.py index 4fc69e689b6..916b1eb1a1f 100644 --- a/src/sage/graphs/generators/smallgraphs.py +++ b/src/sage/graphs/generators/smallgraphs.py @@ -5642,7 +5642,7 @@ def pi_vec(x): # Associate a matrix to every entry of W int_to_matrix = {0: matrix.zero(45)} for i in range(15): - vec = [frozenset([]), L[0, 0], L[1, 0], L[2, 0], L[3, 0]] + vec = [frozenset(), L[0, 0], L[1, 0], L[2, 0], L[3, 0]] vec = f_pow(pi_vec, i % 3, vec) vec = f_pow(sigma2, i % 5, vec) int_to_matrix[i + 1] = N(vec) diff --git a/src/sage/matrix/matrix_modn_sparse.pyx b/src/sage/matrix/matrix_modn_sparse.pyx index 33056c221ce..8f5d657a464 100644 --- a/src/sage/matrix/matrix_modn_sparse.pyx +++ b/src/sage/matrix/matrix_modn_sparse.pyx @@ -361,7 +361,7 @@ cdef class Matrix_modn_sparse(Matrix_sparse): cdef c_vector_modint* v # Build a table that gives the nonzero positions in each column of right - nonzero_positions_in_columns = [set([]) for _ in range(right._ncols)] + nonzero_positions_in_columns = [set() for _ in range(right._ncols)] cdef Py_ssize_t i, j, k for i from 0 <= i < right._nrows: v = &(right.rows[i]) diff --git a/src/sage/matrix/matrix_rational_sparse.pyx b/src/sage/matrix/matrix_rational_sparse.pyx index 8e9898642c3..ffe11128dd4 100644 --- a/src/sage/matrix/matrix_rational_sparse.pyx +++ b/src/sage/matrix/matrix_rational_sparse.pyx @@ -236,7 +236,7 @@ cdef class Matrix_rational_sparse(Matrix_sparse): cdef mpq_vector* v # Build a table that gives the nonzero positions in each column of right - nonzero_positions_in_columns = [set([]) for _ in range(right._ncols)] + nonzero_positions_in_columns = [set() for _ in range(right._ncols)] cdef Py_ssize_t i, j, k for i in range(right._nrows): v = &(right._matrix[i]) diff --git a/src/sage/matroids/dual_matroid.py b/src/sage/matroids/dual_matroid.py index 59dcfa73cc9..f930cafd5c7 100644 --- a/src/sage/matroids/dual_matroid.py +++ b/src/sage/matroids/dual_matroid.py @@ -332,8 +332,8 @@ def _minor(self, contractions=None, deletions=None): EXAMPLES:: sage: M = matroids.catalog.Vamos().dual() - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) Dual of 'M / {'b', 'c'} \ {'a'}, where M is Vamos: Matroid of rank 4 on 8 elements with circuit-closures {3: {{'a', 'b', 'c', 'd'}, {'a', 'b', 'e', 'f'}, diff --git a/src/sage/matroids/linear_matroid.pyx b/src/sage/matroids/linear_matroid.pyx index 7259f9f1dc0..58ff8b8def1 100644 --- a/src/sage/matroids/linear_matroid.pyx +++ b/src/sage/matroids/linear_matroid.pyx @@ -1332,8 +1332,8 @@ cdef class LinearMatroid(BasisExchangeMatroid): sage: M = Matroid(groundset='abcdefgh', ring=GF(5), ....: reduced_matrix=[[2, 1, 1, 0], ....: [1, 1, 0, 1], [1, 0, 1, 1], [0, 1, 1, 2]]) - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) Linear matroid of rank 3 on 5 elements represented over the Finite Field of size 5 """ @@ -2847,7 +2847,7 @@ cdef class LinearMatroid(BasisExchangeMatroid): if sol: if certificate: (certX, certY) = cert_pair - cert = set([]) + cert = set() for x in certX: cert.add(dX[x]) for y in certY: @@ -3783,8 +3783,8 @@ cdef class BinaryMatroid(LinearMatroid): EXAMPLES:: sage: M = matroids.catalog.Fano() - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) Binary matroid of rank 2 on 4 elements, type (0, 6) """ self._move_current_basis(contractions, deletions) @@ -4720,8 +4720,8 @@ cdef class TernaryMatroid(LinearMatroid): EXAMPLES:: sage: M = matroids.catalog.P8() - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) Ternary matroid of rank 3 on 5 elements, type 0- """ self._move_current_basis(contractions, deletions) @@ -5488,8 +5488,8 @@ cdef class QuaternaryMatroid(LinearMatroid): EXAMPLES:: sage: M = matroids.catalog.Q10() # needs sage.rings.finite_rings - sage: N = M._minor(contractions=set(['a']), deletions=set([])) # needs sage.rings.finite_rings - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) # needs sage.rings.finite_rings + sage: N = M._minor(contractions=set(['a']), deletions=set()) # needs sage.rings.finite_rings + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) # needs sage.rings.finite_rings Quaternary matroid of rank 4 on 7 elements """ self._move_current_basis(contractions, deletions) diff --git a/src/sage/matroids/matroid.pyx b/src/sage/matroids/matroid.pyx index d4a71e8a38e..c308c492022 100644 --- a/src/sage/matroids/matroid.pyx +++ b/src/sage/matroids/matroid.pyx @@ -894,7 +894,7 @@ cdef class Matroid(SageObject): True """ cdef set XX = set(X) - cdef set res = set([]) + cdef set res = set() cdef int r = self._rank(frozenset(X)) for e in Y: XX.add(e) @@ -1155,8 +1155,8 @@ cdef class Matroid(SageObject): EXAMPLES:: sage: M = matroids.catalog.Vamos() - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['b', 'c'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['b', 'c'])) M / {'a'} \ {'b', 'c'}, where M is Vamos: Matroid of rank 4 on 8 elements with circuit-closures {3: {{'a', 'b', 'c', 'd'}, {'a', 'b', 'e', 'f'}, @@ -2603,7 +2603,7 @@ cdef class Matroid(SageObject): sage: [sorted(X) for X in CC[3]] [['a', 'b', 'c', 'd', 'e', 'f', 'g']] """ - CC = [set([]) for r in range(self.rank() + 1)] + CC = [set() for r in range(self.rank() + 1)] for C in self.circuits_iterator(): CC[len(C) - 1].add(self.closure(C)) return {r: CC[r] for r in range(self.rank() + 1) if CC[r]} @@ -2634,7 +2634,7 @@ cdef class Matroid(SageObject): ... KeyError: 3 """ - CC = [set([]) for r in range(self.rank() + 1)] + CC = [set() for r in range(self.rank() + 1)] for C in self.nonspanning_circuits_iterator(): CC[len(C) - 1].add(self.closure(C)) return {r: CC[r] for r in range(self.rank() + 1) if CC[r]} @@ -4944,7 +4944,7 @@ cdef class Matroid(SageObject): """ E = set(self.groundset()) E.difference_update(self._closure(frozenset())) # groundset minus loops - res = set([]) + res = set() while E: e = E.pop() @@ -4980,7 +4980,7 @@ cdef class Matroid(SageObject): """ E = set(self.groundset()) E.difference_update(self._coclosure(frozenset())) # groundset minus coloops - res = set([]) + res = set() while E: e = E.pop() @@ -5412,7 +5412,7 @@ cdef class Matroid(SageObject): for R1 in map(set, combinations(R, r2)): R2 = R - R1 # F is the set of elements cannot be in the extension of Q1 - F = set([]) + F = set() U = E - R # if Q1|R1 is full if m-len(Q1)-len(R1) == 0: @@ -5925,14 +5925,14 @@ cdef class Matroid(SageObject): ....: [0,0,0,0,1,1,1,1,0,0,1,1], ....: [0,0,0,0,0,0,0,0,1,1,1,1]]) sage: M._shifting_all(M.basis(), - ....: set([0,1]), set([0,1]), set([]), set([]), 3) + ....: set([0,1]), set([0,1]), set(), set(), 3) (False, None) sage: M = Matroid(field=GF(2), reduced_matrix=[[1,0,1,1,1], ....: [1,1,1,1,0], ....: [0,1,1,1,0], ....: [0,0,0,1,1]]) sage: M._shifting_all(M.basis(), - ....: set([0,1]), set([5,8]), set([]), set([]), 3)[0] + ....: set([0,1]), set([5,8]), set(), set(), 3)[0] True """ Y = self.groundset()-X @@ -5986,14 +5986,14 @@ cdef class Matroid(SageObject): ....: [0,0,0,0,1,1,1,1,0,0,1,1], ....: [0,0,0,0,0,0,0,0,1,1,1,1]]) sage: M._shifting(M.basis(), - ....: set([0,1]), set([0,1]), set([]), set([]), 3) + ....: set([0,1]), set([0,1]), set(), set(), 3) (False, None) sage: M = Matroid(field=GF(2), reduced_matrix=[[1,0,1,1,1], ....: [1,1,1,1,0], ....: [0,1,1,1,0], ....: [0,0,0,1,1]]) sage: M._shifting(M.basis(), - ....: set([0,1]), set([5,8]), set([]), set([4]), 3)[0] + ....: set([0,1]), set([5,8]), set(), set([4]), 3)[0] True """ @@ -6954,7 +6954,7 @@ cdef class Matroid(SageObject): raise ValueError("nonnegative weights were expected.") wt = sorted(wt, reverse=True) Y = [e for (w, e) in wt] - res = set([]) + res = set() r = 0 for e in Y: res.add(e) diff --git a/src/sage/matroids/minor_matroid.py b/src/sage/matroids/minor_matroid.py index 3bfec4bf2a4..871a8892579 100644 --- a/src/sage/matroids/minor_matroid.py +++ b/src/sage/matroids/minor_matroid.py @@ -324,8 +324,8 @@ def _minor(self, contractions, deletions): sage: from sage.matroids.advanced import * sage: M = MinorMatroid(matroids.catalog.Vamos(), contractions=set('c'), deletions={'b', 'f'}) - sage: N = M._minor(contractions=set(['a']), deletions=set([])) - sage: N._minor(contractions=set([]), deletions=set(['d'])) + sage: N = M._minor(contractions=set(['a']), deletions=set()) + sage: N._minor(contractions=set(), deletions=set(['d'])) M / {'a', 'c'} \ {'b', 'd', 'f'}, where M is Vamos: Matroid of rank 4 on 8 elements with circuit-closures {3: {{'a', 'b', 'c', 'd'}, {'a', 'b', 'e', 'f'}, diff --git a/src/sage/matroids/utilities.py b/src/sage/matroids/utilities.py index eb8b493c2e0..cb462793050 100644 --- a/src/sage/matroids/utilities.py +++ b/src/sage/matroids/utilities.py @@ -429,7 +429,7 @@ def spanning_stars(M): # remove low degree vertices H = [] # candidate vertices - V_0 = set([]) + V_0 = set() d = 0 while G.order(): x, d = min(G.degree_iterator(labels=True), key=itemgetter(1)) @@ -444,7 +444,7 @@ def spanning_stars(M): # greedily remove vertices G2 = G.copy() # set of picked vertices - V_1 = set([]) + V_1 = set() while G2.order(): # choose vertex with maximum degree in G2 x, d = max(G2.degree_iterator(labels=True), key=itemgetter(1)) diff --git a/src/sage/rings/polynomial/pbori/specialsets.py b/src/sage/rings/polynomial/pbori/specialsets.py index 9c5b4bdefc8..8ad680857ba 100644 --- a/src/sage/rings/polynomial/pbori/specialsets.py +++ b/src/sage/rings/polynomial/pbori/specialsets.py @@ -87,7 +87,7 @@ def power_set(variables): print(list(all_monomials_of_degree_d(1, []))) print(list(power_set([Variable(i) for i in range(2)]))) print(list(power_set([Variable(i) for i in range(4)]))) - print(list(power_set([]))) + print(list(power_set())) # every monomial in the first 8 var, which is at most linear in the first 5 print(list(mod_mon_set( power_set([Variable(i) for i in range(8)]), diff --git a/src/sage/symbolic/relation.py b/src/sage/symbolic/relation.py index d0098871834..01f5bd147e9 100644 --- a/src/sage/symbolic/relation.py +++ b/src/sage/symbolic/relation.py @@ -1807,7 +1807,7 @@ def solve_ineq_fourier(ineq, vars=None): - Robert Marik (01-2010) """ if vars is None: - setvars = set([]) + setvars = set() for i in (ineq): setvars = setvars.union(set(i.variables())) vars = list(setvars)