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Equation 13 · Part 2 · Why Average Success Rate Hides the Failures That Matter Most

subscript

BiB_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

where BiB_i is the blast radius assigned to failure mode i : how much of a system, how much data, how many users or how much liability a given failure could plausibly reach, drawn from a small number of severity tiers rather than treated as a continuous unknown. This is not a hypothetical scoring scheme; tiered, severity-weighted evaluation of exactly this shape is already how the field’s two most cited frontier-risk frameworks operate at the level of an entire model. Anthropic’s Responsible Scaling Policy defines a ladder of AI Safety Levels, modelled loosely on biosafety-level containment standards, under which a model’s required safety, security and deployment safeguards scale with the…

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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 surrounding passage

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