A counterexample is a form of counter proof.
Given a hypothesis stating that is true for all , show that there exists a such that is false, contradicting the hypothesis.
A counterexample is a form of counter proof.
Given a hypothesis stating that is true for all , show that there exists a such that is false, contradicting the hypothesis.
This entry contributed by Wiktor K. Macura
Macura, Wiktor K. "Counterexample." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/Counterexample.html