§4.4.(c) Mapping the result of a base method

In an after callin binding, the right-hand side of a parameter mapping may use the identifier result to refer to the result of the base method.

An after callin binding can, however, not influence the result of the base method, thus mappings with the -> token are not allowed for after callin bindings. For before mappings using the -> token is already ruled out by §4.4.(a)