Small improvement in treatment of symbol attributes of free module bases

Author: egourgoulhon

src/sage/manifolds/differentiable/tangent_space.py

@@ -205,12 +205,13 @@ def __init__(self, point):
             # only if it is a frame on the current manifold:
             if frame.destination_map().is_identity():
                 if point in frame._domain:
+                    coframe = frame.coframe()
                     basis = self.basis(frame._symbol,
                                        latex_symbol=frame._latex_symbol,
                                        indices=frame._indices,
                                        latex_indices=frame._latex_indices,
-                                       symbol_dual=frame._symbol_dual,
-                                       latex_symbol_dual=frame._latex_symbol_dual)
+                                       symbol_dual=coframe._symbol,
+                                       latex_symbol_dual=coframe._latex_symbol)
                     self._frame_bases[frame] = basis
         # The basis induced by the default frame of the manifold subset
         # in which the point has been created is declared the default

src/sage/tensor/modules/free_module_basis.py

@@ -268,6 +268,10 @@ def set_name(self, symbol, latex_symbol=None, indices=None,
             pos = "^"
         if latex_symbol is None:
             latex_symbol = symbol
+        self._symbol = symbol
+        self._latex_symbol = latex_symbol
+        self._indices = indices
+        self._latex_indices = latex_indices
         # Text symbols:
         if isinstance(symbol, (list, tuple)):
             if len(symbol) != n:
@@ -576,9 +580,6 @@ def __init__(self, fmodule, symbol, latex_symbol=None, indices=None,
         Basis_abstract.__init__(self, fmodule, symbol, latex_symbol, indices,
                                 latex_indices)
         # The basis is added to the module list of bases
-        for other in fmodule._known_bases:
-            if symbol == other._symbol:
-                raise ValueError("the {} already exist on the {}".format(other, fmodule))
         fmodule._known_bases.append(self)
         # The individual vectors:
         vl = list()
@@ -696,9 +697,6 @@ def _new_instance(self, symbol, latex_symbol=None, indices=None,
             Dual basis (E^x,E^y,E^z) on the Rank-3 free module M over the Integer Ring
 
         """
-        if isinstance(symbol, list):
-            symbol = tuple(symbol)  # must be a tuple for unique representation
-                                    # of FreeModuleBasis
         return FreeModuleBasis(self._fmodule, symbol, latex_symbol=latex_symbol,
                                indices=indices, latex_indices=latex_indices,
                                symbol_dual=symbol_dual,