← All parts of this equation

Equation 7 · Part 2 · Comparing the Main Approaches to AI Inference Economics

subscript

PrP_r
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

Here the break-even arithmetic is genuinely simple, and worth writing down, because it is the one place in this comparison where a clean model — not a ranking of vendors — is possible. Let a reserved commitment cost PrP_r per accelerator-hour, and let the on-demand or serverless rate that would otherwise serve the same throughput cost PdP_d per accelerator-hour at full utilization. If the buyer’s realized utilization of the reserved capacity is u ∈\in (0, 1] , the reserved option is cheaper exactly when

Read this part in the article →

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.