\to

→ — arrows

An arrow means either "approaches" (in a limit), "is changed to" (a new value), or, pointing left, "is set to" (like = in code).

$p_j \to 0$ means " $p_j$ approaches zero". $\theta_{\text{base}} = 10{,}000 \longrightarrow 500{,}000$ means the constant was changed from 10,000 to 500,000. $z_i \longleftarrow \dots$ is an assignment: replace $z_i$ with the right-hand side, like z[i] = ... in code.

An arrow with a condition written under it, such as $\xrightarrow[T-t\to\infty]{}$ , says what the quantity approaches and what change drives it there.

Where the course uses it

2.1 Derivatives: Slopes and the Rules for Finding Them · Module 2, Calculus and Optimizationfirst use
2.4 Gradient Descent · Module 2, Calculus and Optimization
4.3 Logits, Softmax, and Cross-Entropy · Module 4, How a Model Learns From Data
5.4 Vanishing and Exploding Gradients · Module 5, Sequences Before Transformers
10.2 AdamW · Module 10, Pretraining
12.3 Decoding: From Logits to Text · Module 12, Generation
15.2 Stretching RoPE, and ALiBi · Module 15, The LLaMA Block
15.5 Grouped-Query Attention · Module 15, The LLaMA Block
26.1 Connecting Vision to Language · Module 26, Vision-Language Models
27.2 The Alignment Problem and the Blank · Module 27, Recognition: OCR and Speech With CTC

Related terms

lim — limitRead "the limit as T goes to 0". It is the value a quantity gets closer and closer to as something is pushed toward an extreme, even if that extreme can't be plugged in directly.