[Chapter 8] Notation inconsistency in RoPE formula (variable t vs i) (Page 60)

[Sameta-cani]

Location

• File: chapters/nlp-book-chapter8.pdf
• Page: 60
• Section: 8.3.5.3 Rotary Positional Embedding

Problem Description
I found a notation inconsistency in the description of Rotary Positional Embeddings (RoPE).
In the text, the position is defined as $t$ ("When reaching position $t$..."); however, the formula uses $i$ inside the rotation term ( $\text{Ro}(\mathbf{x}, i\theta)$ ).

Suggested Fix
To maintain consistency with the text context, the variable in the formula should be updated from $i$ to $t$.

• Current: $\text{Ro}(\mathbf{x}, i\theta)$
• Correction: $\text{Ro}(\mathbf{x}, t\theta)$

This clarifies that the rotation depends on the position $t$.

Thank you!

[xiaotong]

Yes, this is a typo. I will correct it. Thank you!