diff --git a/README.md b/README.md
index ebb6c1fa..eee342ae 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ We are building a python library of procedural dataset generators and algorithmi
 
 The goal is to generate virtually infinite data with adjustable complexity.
 
+Algorithmic verification allows to train on tasks like Rubik‘s cube or [Countdown](https://en.wikipedia.org/wiki/Countdown_(game_show)#Numbers_Round) which have many correct solutions.
+
 ## Set up for development
 1. Clone the project
 ```
@@ -38,6 +40,8 @@ data = reasoning_gym.create_dataset('leg_counting', size=10, seed=42)
 for i, x in enumerate(data):
     print(f'{i}: q="{x['question']}", a="{x['answer']}"')
     print('metadata:', x['metadata'])
+    # use the dataset's `score_answer` method for algorithmic verification
+    assert data.score_answer(answer=x['answer'], entry=x) == 1.0
 ```
 
 Output:
diff --git a/reasoning_gym/graphs/quantum_lock.py b/reasoning_gym/graphs/quantum_lock.py
index 10e83fdd..402b6f0c 100644
--- a/reasoning_gym/graphs/quantum_lock.py
+++ b/reasoning_gym/graphs/quantum_lock.py
@@ -1,7 +1,7 @@
-from dataclasses import dataclass
 import re
-from random import Random
 from collections import deque
+from dataclasses import dataclass
+from random import Random
 from typing import Any, Optional
 
 from ..factory import ProceduralDataset, register_dataset
diff --git a/tests/test_quantum_lock.py b/tests/test_quantum_lock.py
index a004afc9..69162750 100644
--- a/tests/test_quantum_lock.py
+++ b/tests/test_quantum_lock.py
@@ -1,4 +1,5 @@
 import pytest
+
 from reasoning_gym.graphs.quantum_lock import QuantumLockConfig, QuantumLockDataset
 
 
@@ -53,20 +54,20 @@ def test_quantumlock_button_states():
 
     for item in dataset:
         buttons = item["metadata"]["buttons"]
-        
+
         # Check button properties
         for btn in buttons:
             assert "name" in btn
             assert "type" in btn
             assert "value" in btn
             assert "active_state" in btn
-            
+
             # Verify button name format
             assert btn["name"] in ["A", "B", "C"]
-            
+
             # Verify operation type
             assert btn["type"] in ["add", "subtract", "multiply"]
-            
+
             # Verify state constraints
             assert btn["active_state"] in ["red", "green", "any"]
 
@@ -79,19 +80,16 @@ def test_quantumlock_solution_validation():
     for item in dataset:
         solution = item["metadata"]["solution_path"]
         target = item["metadata"]["target_value"]
-        
+
         # Test solution simulation
-        final_value = dataset.simulate_sequence(
-            item["metadata"],
-            solution
-        )
+        final_value = dataset.simulate_sequence(item["metadata"], solution)
         assert final_value == target
 
         # Test invalid button sequences
-        assert dataset.simulate_sequence(
-            item["metadata"],
-            ["X", "Y", "Z"]  # Invalid buttons
-        ) == item["metadata"]["initial_value"]
+        assert (
+            dataset.simulate_sequence(item["metadata"], ["X", "Y", "Z"])  # Invalid buttons
+            == item["metadata"]["initial_value"]
+        )
 
 
 def test_quantumlock_scoring():
@@ -101,17 +99,17 @@ def test_quantumlock_scoring():
 
     for item in dataset:
         solution = item["metadata"]["solution_path"]
-        
+
         # Test correct solution
         assert dataset.score_answer(solution, item) == 1.0
-        
+
         # Test empty/None answers
         assert dataset.score_answer(None, item) == 0.0
         assert dataset.score_answer("", item) == 0.1
-        
+
         # Test invalid buttons
         assert dataset.score_answer("XYZ", item) == 0.1
-        
+
         # Test case insensitivity
         if solution:
             lower_solution = "".join(solution).lower()