Equation 13 · Part 1 · Building Production RAG: An Advanced Technical Guide
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→Article meaning
The passage around this formula
where k is the number of candidates handed to the reranker and is the marginal latency per candidate scored. Recall generally improves as k grows, because a larger candidate set is more likely to contain the passage that actually answers the query — but k multiplies the one latency term a team most directly controls, so it is not a value to leave at a copied default. It is a dial to be set from a measured recall-versus- k curve against an explicit latency budget, the same way the hybrid weight is set from a measured recall curve rather than assumed.
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.