diff --git a/src/clingexplaid/cli/clingo_app.py b/src/clingexplaid/cli/clingo_app.py
index 34b17f0..83fdb00 100644
--- a/src/clingexplaid/cli/clingo_app.py
+++ b/src/clingexplaid/cli/clingo_app.py
@@ -183,7 +183,11 @@ def _method_mus(
 
         # Case: Finding a single MUS
         if max_models == -1:
-            control.solve(assumptions=list(assumptions), on_core=cc.shrink)
+
+            def shrink_on_model(core: Sequence[int]) -> None:
+                _ = cc.shrink(core)
+
+            control.solve(assumptions=list(assumptions), on_core=shrink_on_model)
 
             if cc.minimal is None:
                 print("SATISFIABLE: Instance has no MUS")
diff --git a/src/clingexplaid/cli/textual_gui.py b/src/clingexplaid/cli/textual_gui.py
index 2027571..cac4d12 100644
--- a/src/clingexplaid/cli/textual_gui.py
+++ b/src/clingexplaid/cli/textual_gui.py
@@ -53,6 +53,8 @@
 
 
 class Modes(Enum):
+    """Representation of the Clingo-Explaid Modes"""
+
     MODE_MUS = "Minimal Unsatisfiable Subsets"
     MODE_UNSAT_CONSTRAINTS = "Unsatisfiable Constraints"
     MODE_SHOW_DECISIONS = "Show Decisions"
@@ -429,6 +431,7 @@ class ClingexplaidTextualApp(App[int]):
     """A textual app for a terminal GUI to use the clingexplaid functionality"""
 
     # pylint: disable=too-many-instance-attributes
+    # pylint: disable=too-many-public-methods
     # pylint: disable=duplicate-code
 
     CSS = MAIN_CSS
@@ -671,8 +674,8 @@ async def action_mode_show_decisions(self) -> None:
         self.tree_cursor.add(end_string)
 
     async def action_mode_explain(self) -> None:
-        # TODO: Add implementation
-        pass
+        """Action for Explain Mode"""
+        # Add implementation
 
     async def action_solve(self) -> None:
         """
diff --git a/tests/clingexplaid/test_muc.py b/tests/clingexplaid/test_muc.py
index 2ca9224..3c6ecb4 100644
--- a/tests/clingexplaid/test_muc.py
+++ b/tests/clingexplaid/test_muc.py
@@ -3,7 +3,7 @@
 """
 
 import random
-from typing import List, Optional, Set, Tuple
+from typing import List, Optional, Sequence, Set, Tuple
 from unittest import TestCase
 
 import clingo
@@ -34,7 +34,11 @@ def get_mus_of_program(
     assumptions = at.get_assumption_literals(ctl)
 
     cc = CoreComputer(ctl, assumptions)
-    ctl.solve(assumptions=list(assumptions), on_core=cc.shrink)
+
+    def shrink_on_model(core: Sequence[int]) -> None:
+        _ = cc.shrink(core)
+
+    ctl.solve(assumptions=list(assumptions), on_core=shrink_on_model)
 
     # if the instance was satisfiable and the on_core function wasn't called an empty set is returned, else the mus.
     result = cc.minimal if cc.minimal is not None else set()