Bug/fix inappropriate symbol and ! for factorial (#255)

* Updated to Python 3.12

* Handle infinity Unicode symbol and fix infinite value comparison

Added ∞ as an alias for oo so students can use the Unicode infinity
symbol as input. Fixed comparison of infinite expressions by using
direct sympy comparison instead of subtraction, since oo - oo yields
nan rather than 0.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Handled exceptions for is_infinite checks during symbolic expression comparison

* Updated sympy to 1.13

* Updated sympy to 1.14 and mpath to 1.4.1

* Added parametric factorial and double factorial tests; implemented warning for unsupported triple factorial notation

* Update CI to use Python 3.12

* Changed mpmath version

* Switched Dockerfile base image to apt package manager for Git installation.

* Switched to use dnf

* Added find to installed requirements

* Set PYTHONPATH in Dockerfile and updated CMD entrypoint format

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: m-messer

app/evaluation.py

@@ -294,6 +294,10 @@ def evaluation_function(response, answer, params, include_test_data=False) -> di
         if "!" in response:
             evaluation_result.add_feedback(("NOTATION_WARNING_FACTORIAL", symbolic_comparison_internal_messages("NOTATION_WARNING_FACTORIAL")(dict())))
 
+    if "!!!" in response:
+        evaluation_result.add_feedback(
+            ("NOTATION_WARNING_TRIPLE_FACTORIAL", symbolic_comparison_internal_messages("NOTATION_WARNING_TRIPLE_FACTORIAL")(dict())))
+
     reserved_expressions_success, reserved_expressions = parse_reserved_expressions(reserved_expressions_strings, parameters, evaluation_result)
     if reserved_expressions_success is False:
         return evaluation_result.serialise(include_test_data)

app/feedback/symbolic.py

@@ -21,6 +21,7 @@
     "PARSE_ERROR": f"`{inputs.get('x','')}` could not be parsed as a valid mathematical expression. Ensure that correct codes for input symbols are used, correct notation is used, that the expression is unambiguous and that all parentheses are closed.",
     "NOTATION_WARNING_EXPONENT": "Note that `^` cannot be used to denote exponentiation, use `**` instead.",
     "NOTATION_WARNING_FACTORIAL": "Note that `!` cannot be used to denote factorial, use `factorial(...)` instead.",
+    "NOTATION_WARNING_TRIPLE_FACTORIAL": "Note that `!!!` is not supported.",
     "EXPRESSION_NOT_EQUALITY": "The response was an expression but was expected to be an equality.",
     "EQUALITY_NOT_EXPRESSION": "The response was an equality but was expected to be an expression.",
     "EQUALITIES_EQUIVALENT": None,

app/tests/symbolic_evaluation_test.py

@@ -1883,15 +1883,52 @@ def test_sum_in_answer(self, response, answer, value):
         result = evaluation_function(response, answer, params)
         assert result["is_correct"] is value
 
-    def test_exclamation_mark_for_factorial(self):
-        response = "3!"
-        answer = "factorial(3)"
+    @pytest.mark.parametrize(
+        "response, answer, value",
+        [
+            ("3!", "factorial(3)", True),
+            ("(n+1)!", "factorial(n+1)", True),
+            ("n!", "factorial(n)", True),
+            ("a!=b", "factorial(3)", False),
+            ("2*n!", "2*factorial(n)", True),
+            ("3!", "3!", True),
+            ("3*sin(n)!", "3*factorial(sin(n))", True)
+        ]
+    )
+    def test_exclamation_mark_for_factorial(self, response, answer, value):
         params = {
             "strict_syntax": False,
             "elementary_functions": True,
         }
         result = evaluation_function(response, answer, params)
-        assert result["is_correct"] is True
+        assert result["is_correct"] is value
+
+    @pytest.mark.parametrize(
+        "response, answer, value",
+        [
+            ("3!!", "factorial2(3)", True),
+            ("(n+1)!!", "factorial2(n+1)", True),
+            ("n!!", "factorial2(n)", True),
+            ("a!=b", "factorial2(3)", False),
+            ("2*n!!", "2*factorial2(n)", True),
+            ("3!!", "3!!", True),
+        ]
+    )
+    def test_double_exclamation_mark_for_factorial(self, response, answer, value):
+        params = {
+            "strict_syntax": False,
+            "elementary_functions": True,
+        }
+        result = evaluation_function(response, answer, params)
+        assert result["is_correct"] is value
+
+    def test_warning_for_triple_factorial(self):
+        answer = '2^4!'
+        response = '2^4!!!'
+        params = {'strict_syntax': False}
+        result = evaluation_function(response, answer, params, include_test_data=True)
+        assert result["is_correct"] is False
+        assert "NOTATION_WARNING_TRIPLE_FACTORIAL" in result["tags"]
 
     def test_alternatives_to_input_symbols_takes_priority_over_elementary_function_alternatives(self):
         answer = "Ef*exp(x)"