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Equation 9 · Part 2 · The Hardest Unsolved Problems in Open-Weight AI

subscript

sobss_{\text{obs}}
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

A simple decomposition makes clear why this is a measurement problem and not merely an inconvenience. Let sobss_{\text{obs}} be an observed benchmark score, strues_{\text{true}} the underlying capability the benchmark intends to measure, and c the fraction of test instances the model has effectively memorized, whether verbatim or through a rephrased variant. If a memorized instance is answered correctly with certainty, then approximately

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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.

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Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.