Fixing an immutability issue with relabelled Cartan types.

sagemath · Mar 29, 2022 · b9bee75 · b9bee75
1 parent 0bac55b
commit b9bee75
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/src/sage/combinat/root_system/type_relabel.py b/src/sage/combinat/root_system/type_relabel.py
@@ -404,6 +404,7 @@ def type(self):
  """
  return self._type.type()
 
+ @cached_method
  def coxeter_diagram(self):
  """
  Return the Coxeter diagram for ``self``.
@@ -416,9 +417,7 @@ def coxeter_diagram(self):
  sage: G.edges()
  [(1, 2, 5), (2, 3, 3)]
  """
- result = self._type.coxeter_diagram().copy()
- result.relabel(self._relabelling)
- return result
+ return self._type.coxeter_diagram().relabel(self._relabelling, inplace=False, immutable=True)
 
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