Construction of the Optimal Sequence in Greedy Search

An autoregressive model generates the token sequence $y = (\text{'The'}, \text{'quick'}, \text{'brown'}, \text{'fox'})$, where $y_1 = \text{'The'}$, $y_2 = \text{'quick'}$, and so on. What does the notation $y_{<3}$ represent in this specific sequence?

True or False: For an autoregressive model generating the output sequence $y = (y_1, y_2, y_3, y_4)$, the notation $y_{<4}$ represents the complete subsequence $(y_1, y_2, y_3, y_4)$.

Formula for Constructing Top-K Candidate Sequences

An autoregressive language model is generating a sequence of tokens, one at a time. To predict the fifth token in the sequence, denoted as $y_5$, the model uses all the previously generated tokens as context. The standard notation for this preceding subsequence of tokens is ____.