Glossary · Evaluator mechanisms
Soundness
A verifier V_ψ is sound when V_ψ(y) = 1 implies ψ(y) = 1: nothing it accepts violates the formal property, provided the verifier and its configured trusted base behave as claimed.
Defined in
Handbook · FoundationsThe verification hierarchy, demotedFormal > execution > learned judges > intrinsic signals. A useful prior on how grounded a signal is, never a verdict on validity.Related terms
- Completeness
- Whether a verifier accepts every true instance of its property. Distinct from soundness, and often traded for tractability. Passing tests establishes neither: it means no tested counterexample was found.
- Configured trusted base
- Everything a formal guarantee is relative to: permitted axioms, theorem statements, checker version, kernel configuration, environment assumptions, and whether the optimizer can modify any of them. The Goodhart boundary moves here rather than disappearing.
- Verifier
- Strictly, an evaluator with a soundness guarantee relative to a formal specification. In loose usage it often means a deterministic or execution checker.
Where it comes up
- Vocabulary without category errorsHandbook · Foundations
- Mechanism familiesHandbook · Instrument
- Notation and formula cardHandbook · Reference