# Set assumptions for TypedSymbol/cast_func/IntegerFunctionTwoArgsMixIn the SymPy way

After having a nearly week long discussion on assumptions in my SymPy PR, I got some idea of how the assumptions in SymPy are working.

It's interesting that you can use `Function.__new__(cls, integer=True)`

for `UndefinedFunction`

s like `Function('f', interger=True)`

but not for subclassese of `Function`

.

Now things like `(2*f.shape[0]).is_integer`

are working.

Edited by Stephan Seitz