Equation 6 · Part 2 · OpenAI Model Systems from First Principles: Weights, Post-Training, and Inference Compute
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 is pretraining compute, is post-training compute, Q is the number of served requests over the system’s life, and is the mean compute per request. Until roughly 2024 the third term was treated as approximately fixed for a given model, and public discussion of capability collapsed onto the first. That assumption no longer holds. On current OpenAI models, is a parameter the caller sets: as verified on 8 August 2026, the model guidance documents a reasoninffort control taking the values none , low , medium , high , xhigh , and max , alongside a separate text.verbosity setting [ 2 ] .
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.