Minor changes.

pyop3/array/petsc.py

@@ -380,8 +380,8 @@ def _map(self, axes):
         loop_index = just_one(axes.outer_loops)
         iterset = AxisTree(loop_index.iterset.node_map)
         map_axes = iterset.add_subtree(axes, *iterset.leaf)
-        global_map = HierarchicalArray(map_axes, dtype=IntType)
-        global_map = global_map[loop_index.local_index]
+        mapping = HierarchicalArray(map_axes, dtype=IntType)
+        mapping = mapping[loop_index.local_index]
         for idxs in my_product(axes.outer_loops):
             # target_indices = {idx.index.id: idx.target_exprs for idx in idxs}
             target_indices = merge_dicts([idx.replace_map for idx in idxs])
@@ -390,20 +390,18 @@ def _map(self, axes):
                 offset = axes.unindexed.offset(
                     p.target_exprs, p.target_path, loop_exprs=target_indices
                 )
-                global_map.set_value(
+                mapping.set_value(
                     p.source_exprs,
                     offset,
                     p.source_path,
                     loop_exprs=target_indices,
                 )
-        return global_map
+        return mapping
 
 
     @cached_property
     @PETSc.Log.EventDecorator()
     def maps(self):
-        from pyop3.axtree.layout import my_product
-
         # TODO: Don't think these need to be lists here.
         # FIXME: This will only work for singly-nested matrices
         if self.nested: