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Equation 9 · Part 2 · Comparing Frontier Model Pricing Without Comparing Apples to Oranges

subscript

ρi\rho_i
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.

The passage around this formula

Collecting every distinction above into one expression makes explicit what a bare price comparison assumes without saying so. For vendor i , let piinp^{\text{in}}_i and pioutp^{\text{out}}_i be the published input and output rates; let κi\kappa_i be a tokenizer expansion factor, the number of tokens vendor i ’s own tokenizer needs to encode one fixed reference passage, normalised so κi\kappa_i = 1 for whichever vendor is used as the baseline; let hih_i be the fraction of input served from cache and γi\gamma_i the cache-read multiplier; and let ρi\rho_i be the ratio of total output tokens generated, visible answer plus hidden reasoning, to the visible answer alone. A workload’s realised cost per completed task…

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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.