diff --git a/mathics/builtin/assignment.py b/mathics/builtin/assignment.py
index b6af29319..cc5ea64e4 100644
--- a/mathics/builtin/assignment.py
+++ b/mathics/builtin/assignment.py
@@ -315,9 +315,8 @@ def assign_elementary(self, lhs, rhs, evaluation, tags=None, upset=False):
             #    $Context = $Context <> "test`"
             #
             if new_context.startswith("`"):
-                new_context = (
-                    evaluation.definitions.get_current_context()
-                    + new_context.lstrip("`")
+                new_context = evaluation.definitions.get_current_context() + new_context.lstrip(
+                    "`"
                 )
 
             evaluation.definitions.set_current_context(new_context)
@@ -1320,7 +1319,7 @@ def do_clear(self, definition):
     def apply_all(self, evaluation):
         "ClearAll[System`All]"
         evaluation.cache_result = False
-        evaluation.cache_expr = {}        
+        evaluation.cache_expr = {}
         evaluation.definitions.set_user_definitions({})
         evaluation.definitions.clear_pymathics_modules()
         return
@@ -1929,7 +1928,7 @@ class LoadModule(Builtin):
 
     def apply(self, module, evaluation):
         "LoadModule[module_String]"
-        evaluation.cache_result = False        
+        evaluation.cache_result = False
         try:
             evaluation.definitions.load_pymathics_module(module.value)
         except PyMathicsLoadException:
diff --git a/mathics/builtin/datentime.py b/mathics/builtin/datentime.py
index eb1cc4a00..0ab4bc004 100644
--- a/mathics/builtin/datentime.py
+++ b/mathics/builtin/datentime.py
@@ -213,8 +213,8 @@ def apply(self, expr, evaluation):
         "Timing[expr_]"
         start = time.process_time()
         result = expr.evaluate(evaluation)
-        evaluation.cache_result = False      
         stop = time.process_time()
+        evaluation.cache_result = False
         return Expression("List", Real(stop - start), result)
 
 
diff --git a/mathics/builtin/files_io/files.py b/mathics/builtin/files_io/files.py
index 04c6a3f18..db4fcecde 100644
--- a/mathics/builtin/files_io/files.py
+++ b/mathics/builtin/files_io/files.py
@@ -2152,7 +2152,7 @@ class Put(BinaryOperator):
     def apply(self, exprs, filename, evaluation):
         "Put[exprs___, filename_String]"
         evaluation.cache_result = False
-        
+
         instream = Expression("OpenWrite", filename).evaluate(evaluation)
         if len(instream.leaves) == 2:
             name, n = instream.leaves
@@ -2165,7 +2165,7 @@ def apply(self, exprs, filename, evaluation):
     def apply_input(self, exprs, name, n, evaluation):
         "Put[exprs___, OutputStream[name_, n_]]"
         evaluation.cache_result = False
-        
+
         stream = stream_manager.lookup_stream(n.get_int_value())
 
         if stream is None or stream.io.closed:
@@ -2186,7 +2186,7 @@ def apply_input(self, exprs, name, n, evaluation):
     def apply_default(self, exprs, filename, evaluation):
         "Put[exprs___, filename_]"
         evaluation.cache_result = False
-        
+
         expr = Expression("Put", exprs, filename)
         evaluation.message("General", "stream", filename)
         return expr
@@ -2248,7 +2248,7 @@ class PutAppend(BinaryOperator):
     def apply(self, exprs, filename, evaluation):
         "PutAppend[exprs___, filename_String]"
         evaluation.cache_result = False
-        
+
         instream = Expression("OpenAppend", filename).evaluate(evaluation)
         if len(instream.leaves) == 2:
             name, n = instream.leaves
@@ -2261,7 +2261,7 @@ def apply(self, exprs, filename, evaluation):
     def apply_input(self, exprs, name, n, evaluation):
         "PutAppend[exprs___, OutputStream[name_, n_]]"
         evaluation.cache_result = False
-        
+
         stream = stream_manager.lookup_stream(n.get_int_value())
 
         if stream is None or stream.io.closed:
@@ -2282,7 +2282,7 @@ def apply_input(self, exprs, name, n, evaluation):
     def apply_default(self, exprs, filename, evaluation):
         "PutAppend[exprs___, filename_]"
         evaluation.cache_result = False
-        
+
         expr = Expression("PutAppend", exprs, filename)
         evaluation.message("General", "stream", filename)
         return expr
@@ -2452,7 +2452,7 @@ class FilePrint(Builtin):
     def apply(self, path, evaluation, options):
         "FilePrint[path_ OptionsPattern[FilePrint]]"
         evaluation.cache_result = False
-        
+
         pypath = path.to_python()
         if not (
             isinstance(pypath, str)
@@ -2584,13 +2584,13 @@ def apply_input(self, name, n, evaluation):
     def apply_output(self, name, n, evaluation):
         "StreamPosition[OutputStream[name_, n_]]"
         evaluation.cache_result = False
-        
+
         self.input_apply(name, n, evaluation)
 
     def apply_default(self, stream, evaluation):
         "StreamPosition[stream_]"
         evaluation.cache_result = False
-        
+
         evaluation.message("General", "stream", stream)
         return
 
@@ -2639,7 +2639,7 @@ class SetStreamPosition(Builtin):
     def apply_input(self, name, n, m, evaluation):
         "SetStreamPosition[InputStream[name_, n_], m_]"
         evaluation.cache_result = False
-        
+
         stream = stream_manager.lookup_stream(n.get_int_value())
 
         if stream is None or stream.io is None or stream.io.closed:
@@ -2672,13 +2672,13 @@ def apply_input(self, name, n, m, evaluation):
     def apply_output(self, name, n, m, evaluation):
         "SetStreamPosition[OutputStream[name_, n_], m_]"
         evaluation.cache_result = False
-        
+
         return self.apply_input(name, n, m, evaluation)
 
     def apply_default(self, stream, evaluation):
         "SetStreamPosition[stream_]"
         evaluation.cache_result = False
-        
+
         evaluation.message("General", "stream", stream)
         return
 
@@ -2854,7 +2854,7 @@ class InputStream(Builtin):
     def apply(self, name, n, evaluation):
         "InputStream[name_, n_]"
         evaluation.cache_result = False
-        
+
         return
 
 
@@ -2876,7 +2876,7 @@ class OutputStream(Builtin):
     def apply(self, name, n, evaluation):
         "OutputStream[name_, n_]"
         evaluation.cache_result = False
-        
+
         return
 
 
@@ -2905,7 +2905,7 @@ class StringToStream(Builtin):
     def apply(self, string, evaluation):
         "StringToStream[string_]"
         evaluation.cache_result = False
-        
+
         pystring = string.to_python()[1:-1]
         fp = io.StringIO(str(pystring))
 
@@ -2941,13 +2941,13 @@ class Streams(Builtin):
     def apply(self, evaluation):
         "Streams[]"
         evaluation.cache_result = False
-        
+
         return self.apply_name(None, evaluation)
 
     def apply_name(self, name, evaluation):
         "Streams[name_String]"
         evaluation.cache_result = False
-        
+
         result = []
         for stream in stream_manager.STREAMS.values():
             if stream is None or stream.io.closed:
diff --git a/mathics/builtin/files_io/importexport.py b/mathics/builtin/files_io/importexport.py
index f34065ffe..4ac035340 100644
--- a/mathics/builtin/files_io/importexport.py
+++ b/mathics/builtin/files_io/importexport.py
@@ -1207,6 +1207,7 @@ def apply(self, url, elements, evaluation, options={}):
 
         import tempfile
         import os
+
         evaluation.cache_result = False
         py_url = url.get_string_value()
 
diff --git a/mathics/builtin/system.py b/mathics/builtin/system.py
index fbfe39268..b34ff04e8 100644
--- a/mathics/builtin/system.py
+++ b/mathics/builtin/system.py
@@ -623,6 +623,7 @@ class ClearSystemCache(Builtin):
     </dl>
     
     """
+
     def apply_clear(self, evaluation):
         "ClearSystemCache[]"
         evaluation.cache_result = False
@@ -640,4 +641,3 @@ def apply_clear_numeric(self, evaluation):
         evaluation.cache_result = False
         evaluation.definitions.cache_eval = {}
         return
-
diff --git a/mathics/core/evaluation.py b/mathics/core/evaluation.py
index c25c13060..f4c046433 100644
--- a/mathics/core/evaluation.py
+++ b/mathics/core/evaluation.py
@@ -238,6 +238,7 @@ def __init__(
     ) -> None:
         from mathics.core.definitions import Definitions
         from mathics.core.expression import Symbol
+
         if definitions is None:
             definitions = Definitions()
         self.definitions = definitions
@@ -266,7 +267,6 @@ def __init__(
         self.cache_eval = {}
         self.cache_result = False
 
-
     def parse(self, query):
         "Parse a single expression and print the messages."
         from mathics.core.parser import MathicsSingleLineFeeder
diff --git a/mathics/core/expression.py b/mathics/core/expression.py
index 2e3c8defe..01f6361cc 100644
--- a/mathics/core/expression.py
+++ b/mathics/core/expression.py
@@ -144,12 +144,7 @@ def from_python(arg):
         #     return Symbol(arg)
     elif isinstance(arg, dict):
         entries = [
-            Expression(
-                "Rule",
-                from_python(key),
-                from_python(arg[key]),
-            )
-            for key in arg
+            Expression("Rule", from_python(key), from_python(arg[key]),) for key in arg
         ]
         return Expression(SymbolList, *entries)
     elif isinstance(arg, BaseExpression):
@@ -1318,6 +1313,12 @@ def evaluate(self, evaluation) -> typing.Union["Expression", "Symbol"]:
         # evaluation.cache_result can be set here or from inside the evaluation
         # of a branch. Once it is set to false, the result is not cached,
         # and hence, not used.
+        if evaluation.cache_result and (
+            self.get_head_name()
+            in ("System`Out", "System`ToBoxes", "System`MakeBoxes",)
+        ):
+            evaluation.cache_result = False
+
         if evaluation.cache_result:
             expr_hash = str(self.__hash__())
         else:
@@ -1894,21 +1895,17 @@ def thread(self, evaluation, head=None) -> typing.Tuple[bool, "Expression"]:
             return True, Expression(head, *leaves)
 
     def is_numeric(self) -> bool:
-        return (
-            self._head.get_name()
-            in system_symbols(
-                "Sqrt",
-                "Times",
-                "Plus",
-                "Subtract",
-                "Minus",
-                "Power",
-                "Abs",
-                "Divide",
-                "Sin",
-            )
-            and all(leaf.is_numeric() for leaf in self._leaves)
-        )
+        return self._head.get_name() in system_symbols(
+            "Sqrt",
+            "Times",
+            "Plus",
+            "Subtract",
+            "Minus",
+            "Power",
+            "Abs",
+            "Divide",
+            "Sin",
+        ) and all(leaf.is_numeric() for leaf in self._leaves)
         # TODO: complete list of numeric functions, or access NumericFunction
         # attribute