Equation 29 · Part 2 · The Real Economics of Shipping a Model to a Device
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
This is also the economic logic behind platform-level, rather than per-app, on-device models. Apple’s Foundation Models framework gives third-party developers access to the same on-device large language model that powers Apple Intelligence, and Apple’s own announcement states plainly that developers can build with it while “using AI inference that is free of cost” [ 13 ] . Read against the equation above, that phrase is not a claim that inference has no cost — it is a claim about who pays and U . Apple absorbs the variant-matrix engineering and the update-distribution bill once, centrally, at the operating-system level, and amortizes both across every app on every device…
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 surrounding passage
These citations provide research context; check each source for the exact claim it supports.