Fix regression in ElemMultExpr

Caused by 5aa5d53c9375b6b0c98054351a4eb782497da330

1 files changed, 4 insertions, 8 deletions

diff --git a/polymatrix/expression/mixins/elemmultexprmixin.py b/polymatrix/expression/mixins/elemmultexprmixin.py
index f8121a8..330474b 100644
--- a/polymatrix/expression/mixins/elemmultexprmixin.py
+++ b/polymatrix/expression/mixins/elemmultexprmixin.py
@@ -11,6 +11,7 @@ from polymatrix.polymatrix.init import init_poly_matrix, init_broadcast_poly_mat
 from polymatrix.polymatrix.typing import MonomialIndex
 from polymatrix.expression.mixins.expressionbasemixin import ExpressionBaseMixin
 from polymatrix.polymatrix.abc import PolyMatrix
+from polymatrix.polymatrix.utils.mergemonomialindices import merge_monomial_indices
 
 
 class ElemMultExprMixin(ExpressionBaseMixin):
@@ -62,14 +63,9 @@ class ElemMultExprMixin(ExpressionBaseMixin):
 
                     # monomial = tuple(sorted(left_monomial + right_monomial))
 
-                    # TODO: This line broke since the introduction of index
-                    # types, investigate why. Replacing it
-                    # MonomialIndex.product fixes the issue
-
-                    # new_monomial = merge_monomial_indices(
-                    #     (left_monomial, right_monomial)
-                    # )
-                    new_monomial = MonomialIndex.product(left_monomial, right_monomial)
+                    new_monomial = merge_monomial_indices(
+                        (left_monomial, right_monomial)
+                    )
 
                     if new_monomial not in polynomial:
                         polynomial[new_monomial] = 0