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Equation 4 · Part 2 · How Benchmark Contamination Actually Works in Agentic Evaluation

subscript

Δchecker\Delta_{\text{checker}}
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

scapabilitys_{\text{capability}} is the quantity anyone citing the score actually wants: the rate at which the policy would solve genuinely novel instances of this task class. Δleak\Delta_{\text{leak}} is inflation from the environment itself disclosing the solution — through its history, its documentation, or a live network path to the answer. Δchecker\Delta_{\text{checker}} is inflation from a verifier that can be satisfied by something other than a correct solution — a weak test suite, a policy that exploits how success is graded rather than what it is graded on. Δfingerprint\Delta_{\text{fingerprint}} is a shift, in either direction, from the policy detecting that it is inside an evaluation and adjusting its behavior…

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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 →

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