the.com/soundness
the promise that if a proof says yes, reality didn't lie.
means The quality of being solid, healthy, and well-founded — in logic, the property that a system proves only true things.
from From "sound," the adjective meaning healthy or whole, plus the noun-making suffix "-ness." This "sound" comes from Old English "gesund" — hale, uninjured — and is a cousin of German "gesund" (as in "Gesundheit," the blessing after a sneeze that wishes you health). It has nothing to do with "sound" meaning noise, which arrived separately from Latin "sonus." So a sound argument and a sound sleeper share the same root: both are whole and unbroken.
- logic's vow
- every provable statement is actually true
- twin sibling
- completeness is its mirror image
- crypto stakes
- unsound proofs let liars forge valid lies
- hard tradeoff
- systems rarely get both soundness and completeness free
bitcoin's proof of work — cryptographic soundness mechanism securing the network since 2009 through computational difficulty