The largest version of GPT-2, for example, has a fixed length of 1024 tokens, so we | |
cannot calculate \(p_\theta(x_t|x_{<t})\) directly when \(t\) is greater than 1024. | |
Instead, the sequence is typically broken into subsequences equal to the model's maximum input size. If a model's max | |
input size is \(k\), we then approximate the likelihood of a token \(x_t\) by conditioning only on the | |
\(k-1\) tokens that precede it rather than the entire context. |