Objective Function for Policy Optimization

A language model, with parameters represented by θ, is translating the English sentence 'Hello, how are you?' into French. It has already generated the partial translation 'Bonjour, comment'. The model is now deciding the next word. What does the expression π_θ('allez' | 'Hello, how are you?', 'Bonjour, comment') represent in this context?

Match each component of the policy notation π_θ(y_t | X, y_<t) to its correct description in the context of an autoregressive language model.

Appropriateness of Autoregressive Notation