diff --git a/tests/test_reconcile.py b/tests/test_reconcile.py
index 186b5e5..7703921 100644
--- a/tests/test_reconcile.py
+++ b/tests/test_reconcile.py
@@ -4,7 +4,7 @@ import os
 import tempfile
 import textwrap
 
-from conservancy_beancount.reconcile.prototype_amex_reconciler import (
+from conservancy_beancount.reconcile.statement_reconciler import (
     match_statement_and_books,
     remove_payee_junk,
     date_proximity,
@@ -15,6 +15,10 @@ from conservancy_beancount.reconcile.prototype_amex_reconciler import (
     totals,
 )
 
+# These data structures represent individual transactions as taken from the
+# statement ("S") or the books ("B").
+
+# Statement transaction examples.
 S1 = {
     'date': datetime.date(2022, 1, 1),
     'amount': decimal.Decimal('10.00'),
@@ -37,6 +41,7 @@ S3 = {
     'line': 444,
 }
 
+# Books transaction examples.
 B1 = {
     'date': datetime.date(2022, 1, 1),
     'amount': decimal.Decimal('10.00'),
@@ -115,6 +120,11 @@ def test_one_exact_match():
     statement = [S1]
     books = [B1]
     assert match_statement_and_books(statement, books) == [
+        # Match, match, notes.
+        #
+        # The matches are a list so we can implement subset-sum matching where
+        # multiple books transactions may match to a single statement
+        # transaction.
         ([S1], [B1], []),
     ]
 
@@ -180,8 +190,6 @@ def test_payee_mismatch_not_ok_when_multiple_that_amount_and_date():
         ([], [B3_payee_mismatch_2], ['no match']),
     ]
 
-# def test_subset_sum_with_same_date_and_payee():
-
 def test_remove_payee_junk():
     assert remove_payee_junk('WIDGETSRUS INC PAYMENT 1') == 'WIDGETSRUS'
     assert remove_payee_junk('0000010017') == '10017'
@@ -191,7 +199,6 @@ def test_date_proximity():
     assert date_proximity(datetime.date(2021, 8, 23), datetime.date(2021, 8, 23) - datetime.timedelta(days=30)) == 0.5
     assert date_proximity(datetime.date(2021, 8, 23), datetime.date(2021, 8, 23) - datetime.timedelta(days=60)) == 0.0
 
-
 def test_remove_duplicate_words():
     assert remove_duplicate_words('Hi Foo Kow FOO') == 'Hi Foo Kow'
 
@@ -240,7 +247,6 @@ def test_totals():
         ([], [B3_next_day], []),
     ]) == (decimal.Decimal('10'), decimal.Decimal('20'), decimal.Decimal('30'))
 
-
 def test_payee_not_considered_if_check_id_present():
     # These records match aside from check-id.
     statement = [S3]