Update user.md

Author: m-messer

app/docs/user.md

@@ -1,6 +1,7 @@
 # SymbolicEqual
-[!WARNING]
-This feature is deprecated, please use [compareExpressions](https://github.com/lambda-feedback/compareExpressions)
+The function has been deprecated.
+
+[compareExpressions](github.com/lambda-feedback/compareExpressions) is a second-generation evaluation function that is backwards compatible with symbolicEqual and provides more advanced capabilities.
 
 This function utilises the [`SymPy`](https://docs.sympy.org/latest/index.html) to provide a maths-aware comparsion of a student's response to the correct answer. This means that mathematically equivalent inputs will be marked as correct. Note that `pi` is a reserved constant and cannot be used as a symbol name.