Definition. Action serializer [ftip-004P]

Fix the token vocabulary and strings of the tokenizer interface, and the action space \(\mathcal A\) from the declared interactive task realization. An action serializer is a pair of partial maps

\[ \operatorname {enc}:\mathcal A\rightharpoonup \mathcal V^*, \qquad \operatorname {dec}:\mathcal V^*\rightharpoonup \mathcal A. \]

The encoder gives an action a textual representation. The decoder recognizes a completed representation and returns the executable action. A string outside the decoder's domain is malformed; it is not silently promoted to an environment action. For every action in the encoder's domain, the declared pair satisfies \(\operatorname {dec}(\operatorname {enc}(a))=a\).