added simplify_product_function

src/main/py/read_math_function.py

@@ -89,3 +89,7 @@ def simplify_exponential_function(type, function):
         return [f"{new_coefficient}x"]
     else:
         return [f"{new_coefficient}x^{new_exponent}"]
+
+def simplify_product_function(type, function):
+    if type != "p":
+        return False