Merge branch 'u/mantepse/categories_of_lazy_series' of https://github…

….com/sagemath/sagetrac-mirror into u/tscrim/categories_lazy_series-34470
sagemath · Sep 18, 2022 · aa593b5 · aa593b5
2 parents 3d5b8cf + cdf821a
commit aa593b5
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Showing 5 changed files with 634 additions and 107 deletions.
diff --git a/src/sage/combinat/sf/sfa.py b/src/sage/combinat/sf/sfa.py
@@ -1722,6 +1722,24 @@ def degree_zero_coefficient(self):
             """
             return self.coefficient([])
 
+        def is_unit(self):
+            """
+            Return whether this element is a unit in the ring.
+
+            EXAMPLES::
+
+                sage: m = SymmetricFunctions(ZZ).monomial()
+                sage: (2*m[2,1] + m[[]]).is_unit()
+                False
+
+                sage: m = SymmetricFunctions(QQ).monomial()
+                sage: (3/2*m([])).is_unit()
+                True
+            """
+            m = self.monomial_coefficients(copy=False)
+            return len(m) <= 1 and self.coefficient([]).is_unit()
+
+
 #SymmetricFunctionsBases.Filtered = FilteredSymmetricFunctionsBases
 #SymmetricFunctionsBases.Graded = GradedSymmetricFunctionsBases
 

diff --git a/src/sage/combinat/species/generating_series.py b/src/sage/combinat/species/generating_series.py
@@ -143,8 +143,13 @@ def __init__(self, base_ring):
         TESTS::
 
             sage: from sage.combinat.species.generating_series import OrdinaryGeneratingSeriesRing
+            sage: OrdinaryGeneratingSeriesRing.options.halting_precision(15)
             sage: R = OrdinaryGeneratingSeriesRing(QQ)
-            sage: TestSuite(R).run(skip=["_test_associativity", "_test_distributivity", "_test_elements"])
+            sage: TestSuite(R).run()
+
+        Options are remembered across doctests::
+
+            sage: OrdinaryGeneratingSeriesRing.options.halting_precision(None)
         """
         super().__init__(base_ring, names="z")
 
@@ -264,8 +269,13 @@ def __init__(self, base_ring):
         TESTS::
 
             sage: from sage.combinat.species.generating_series import ExponentialGeneratingSeriesRing
+            sage: ExponentialGeneratingSeriesRing.options.halting_precision(15)
             sage: R = ExponentialGeneratingSeriesRing(QQ)
-            sage: TestSuite(R).run(skip=["_test_associativity", "_test_distributivity", "_test_elements"])
+            sage: TestSuite(R).run()
+
+        Options are remembered across doctests::
+
+            sage: ExponentialGeneratingSeriesRing.options.halting_precision(None)
         """
         super().__init__(base_ring, names="z")
 
@@ -546,8 +556,13 @@ def __init__(self, base_ring, sparse=True):
         TESTS::
 
             sage: from sage.combinat.species.generating_series import CycleIndexSeriesRing
+            sage: CycleIndexSeriesRing.options.halting_precision(15)
             sage: R = CycleIndexSeriesRing(QQ)
-            sage: TestSuite(R).run(skip=["_test_elements", "_test_quo_rem"])
+            sage: TestSuite(R).run()
+
+        Options are remembered across doctests::
+
+            sage: CycleIndexSeriesRing.options.halting_precision(None)
         """
         p = SymmetricFunctions(base_ring).power()
         super().__init__(p)
@@ -659,4 +674,3 @@ def LogarithmCycleIndexSeries(R=QQ):
     """
     CIS = CycleIndexSeriesRing(R)
     return CIS(_cl_term)
-