eja: change matrix_space() to use parent().

This allows it to work when the "matrix basis" lives in a Cartesian
product space.

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index db899dd984594bf8ef88cb0e44f3812d2e843996..ae41b8c6e12415d4b940958ca3798749a4e8c7bf 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -737,7 +737,7 @@ class FiniteDimensionalEJA(CombinatorialFreeModule):
         if self.is_trivial():
             return MatrixSpace(self.base_ring(), 0)
         else:
-            return self._matrix_basis[0].matrix_space()
+            return self.matrix_basis()[0].parent()
 
 
     @cached_method