Equation 6 · Part 2 · Naive, Graph, and Agentic: A Systems Comparison of RAG Architectures
Symbol x
What this part means
the writing.
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Lewis and colleagues’ original formulation makes the mechanism explicit: writing x for the query, y for the output, and z for a retrieved passage drawn from a top- k set , the model marginalises over that set,
The passage around this formula
Start with the architecture that gives the pattern its name. A query is encoded, a retriever returns its top- k passages against a fixed index, and a generator conditions on those passages to produce one answer. No step revisits an earlier one. Lewis and colleagues’ original formulation makes the mechanism explicit: writing x for the query, y for the output, and z for a retrieved passage drawn from a top- k set , the model marginalises over that set,
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Sources cited in the article section
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