diff --git a/examples/test_udecimal.py b/examples/test_udecimal.py
index 976494f..04572e0 100644
--- a/examples/test_udecimal.py
+++ b/examples/test_udecimal.py
@@ -2,59 +2,83 @@
 #
 # SPDX-License-Identifier: Unlicense
 # pylint: disable=redefined-builtin,wildcard-import,wrong-import-position,unused-wildcard-import,unused-import,broad-except,undefined-variable,used-before-assignment
-from jepler_udecimal import *
 
-setcontext(ExtendedContext)
-print(Decimal(0))
-print(Decimal("1"))
-print(Decimal("-.0123"))
-print(Decimal(123456))
-print(Decimal("123.45e12345678"))
-print(Decimal("1.33") + Decimal("1.27"))
-print(Decimal("12.34") + Decimal("3.87") - Decimal("18.41"))
-dig = Decimal(1)
-print(dig / Decimal(3))
-getcontext().prec = 18
-print(dig / Decimal(3))
-print(dig.sqrt())
-print(Decimal(3).sqrt())
-print(Decimal(3) ** 123)
-inf = Decimal(1) / Decimal(0)
-print(inf)
-neginf = Decimal(-1) / Decimal(0)
-print(neginf)
-print(neginf + inf)
-print(neginf * inf)
 try:
-    print(dig / 0)
-except Exception as e:
-    print("Division by zero")
-getcontext().traps[DivisionByZero] = 1
-try:
-    print(dig / 0)
-except Exception as e:
-    print("Division by zero")
-c = Context()
-c.traps[InvalidOperation] = 0
-print(c.flags[InvalidOperation])
-try:
-    c.divide(Decimal(0), Decimal(0))
-except Exception as e:
-    print("Division by zero")
-c.traps[InvalidOperation] = 1
-print(c.flags[InvalidOperation])
-c.flags[InvalidOperation] = 0
-print(c.flags[InvalidOperation])
-try:
-    print(c.divide(Decimal(0), Decimal(0)))
-except Exception as e:
-    print("Division by zero")
-print(c.flags[InvalidOperation])
-try:
-    print(c.divide(Decimal(0), Decimal(0)))
-except Exception as e:
-    print("Division by zero")
-print(c.flags[InvalidOperation])
+    from decimal import (
+        Decimal,
+        getcontext,
+        setcontext,
+        ExtendedContext,
+        DivisionByZero,
+        InvalidOperation,
+        Context,
+        localcontext,
+    )
+except ImportError:
+    from jepler_udecimal import (
+        Decimal,
+        getcontext,
+        setcontext,
+        ExtendedContext,
+        DivisionByZero,
+        InvalidOperation,
+        Context,
+        localcontext,
+    )
+
+with localcontext():
+    setcontext(ExtendedContext)
+    print(Decimal(0))
+    print(Decimal("1"))
+    print(Decimal("-.0123"))
+    print(Decimal(123456))
+    print(Decimal("123.45e12345678"))
+    print(Decimal("1.33") + Decimal("1.27"))
+    print(Decimal("12.34") + Decimal("3.87") - Decimal("18.41"))
+    dig = Decimal(1)
+    print(dig / Decimal(3))
+    getcontext().prec = 18
+    print(dig / Decimal(3))
+    print(dig.sqrt())
+    print(Decimal(3).sqrt())
+    print(Decimal(3) ** 123)
+    inf = Decimal(1) / Decimal(0)
+    print(inf)
+    neginf = Decimal(-1) / Decimal(0)
+    print(neginf)
+    print(neginf + inf)
+    print(neginf * inf)
+    try:
+        print(dig / 0)
+    except Exception as e:
+        print("Division by zero")
+    getcontext().traps[DivisionByZero] = 1
+    try:
+        print(dig / 0)
+    except Exception as e:
+        print("Division by zero")
+    c = Context()
+    c.traps[InvalidOperation] = 0
+    print(+c.flags[InvalidOperation])
+    try:
+        c.divide(Decimal(0), Decimal(0))
+    except Exception as e:
+        print("Division by zero")
+    c.traps[InvalidOperation] = 1
+    print(+c.flags[InvalidOperation])
+    c.flags[InvalidOperation] = 0
+    print(+c.flags[InvalidOperation])
+    try:
+        print(c.divide(Decimal(0), Decimal(0)))
+    except Exception as e:
+        print("Division by zero")
+    print(+c.flags[InvalidOperation])
+    try:
+        print(c.divide(Decimal(0), Decimal(0)))
+    except Exception as e:
+        print("Division by zero")
+    print(+c.flags[InvalidOperation])
+
 import jepler_udecimal.utrig
 from jepler_udecimal import Decimal
 
@@ -64,3 +88,18 @@ print(Decimal("-.1").asin())
 print(Decimal(".4").tan())
 print(Decimal(".5").cos())
 print(Decimal(".6").sin())
+print(Decimal("0").sin())
+print(Decimal("360").sin())
+print(Decimal("360e19").sin())
+print(Decimal("NaN").cos())
+print(Decimal("NaN").tan())
+print(Decimal("NaN").sin())
+try:
+    print(Decimal("2").acos())
+except Exception as e:
+    print("exception")
+try:
+    print(Decimal("2").asin())
+except Exception as e:
+    print("exception")
+print(Decimal("2").atan())