Is C++ function belonging to "callable type"

The C++11 standard says:

20.8.1 Definitions [func.def]
1 The following definitions apply to this Clause:
2 A call signature is the name of a return type followed by a parenthesized comma-separated list of zero or
more argument types.
3 A callable type is a function object type (20.8) or a pointer to member.
4 A callable object is an object of a callable type.

So my understanding is, a function is an instance of function type, so function is not "callable type". But definitely we can call functions.

This definition is a bit weird to me. Where did I get wrong?