RationalFunction.__eq__: return NotImplemented for non-RationalFunction

blueprint/src/python/functions.py

@@ -772,6 +772,8 @@ def __repr__(self):
         return f"{sympy.latex(sympy.simplify(self.num / self.den))}"
 
     def __eq__(self, other):
+        if not isinstance(other, RationalFunction):
+            return NotImplemented
         res = self.num * other.den - self.den * other.num
 
         # Direct test if result is numeric

blueprint/src/python/polytope.py

@@ -56,6 +56,8 @@ def __repr__(self):
         return f"{f} = 0"
 
     def __eq__(self, other):
+        if not isinstance(other, Constraint):
+            return NotImplemented
         if (
             len(self.coefficients) != len(other.coefficients)
             or self.inequality_type != other.inequality_type

blueprint/src/python/tests/test_all.py

@@ -35,6 +35,7 @@
 print("All Polytope test cases passed.")
 
 import test_rationalfunction
+import test_rationalfunction_eq_regression
 import test_rational_roots_regression
 
 print("All RationalFunction test cases passed.")

blueprint/src/python/tests/test_rationalfunction_eq_regression.py

@@ -0,0 +1,8 @@
+from functions import RationalFunction as R
+
+
+def run_regressions():
+    assert (R([1]) == 3) is False
+
+
+run_regressions()