- "Impossibility theorem" redirects here. For the theorem on voting systems, see Arrow's impossibility theorem.
A
proof of impossibility, sometimes called a
negative proof or
negative result, is a proof demonstrating that a particular problem cannot be solved, or cannot be solved in general. Often proofs of impossibility have put to rest decades or centuries of work attempting to find a solution. Proofs of impossibility are usually expressible as universal propositions in logic (see
universal quantification).
