eja: don't use product_on_basis() implementation details.

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index ad4e2c7832f961b4893814551657a7a823ac083d..db1e63d1b56ade8d29a33d256ee7e1f2b5e97d31 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -460,9 +460,7 @@ class FiniteDimensionalEJA(CombinatorialFreeModule):
         this algebra was constructed with ``check_axioms=False`` and
         passed an invalid multiplication table.
         """
-        return all( self.product_on_basis(i,j) == self.product_on_basis(i,j)
-                    for i in range(self.dimension())
-                    for j in range(self.dimension()) )
+        return all( x*y == y*x for x in self.gens() for y in self.gens() )
 
     def _is_jordanian(self):
         r"""
@@ -931,7 +929,7 @@ class FiniteDimensionalEJA(CombinatorialFreeModule):
 
         # And to each subsequent row, prepend an entry that belongs to
         # the left-side "header column."
-        M += [ [self.gens()[i]] + [ self.product_on_basis(i,j)
+        M += [ [self.gens()[i]] + [ self.gens()[i]*self.gens()[j]
                                     for j in range(n) ]
                for i in range(n) ]