A constructive proof is a proof that directly provides a specific example, or which gives an algorithm for producing an example. Constructive proofs are also called demonstrative proofs.
Constructive Proof
See also
Existence Problem, Existence Theorem, Nonconstructive Proof, ProofExplore with Wolfram|Alpha
References
Courant, R. and Robbins, H. "The Indirect Method of Proof." §2.4.4 in What Is Mathematics?: An Elementary Approach to Ideas and Methods, 2nd ed. Oxford, England: Oxford University Press, pp. 86-87, 1996.Hoffman, P. The Man Who Loved Only Numbers: The Story of Paul Erdős and the Search for Mathematical Truth. New York: Hyperion, p. 229, 1998.Referenced on Wolfram|Alpha
Constructive ProofCite this as:
Weisstein, Eric W. "Constructive Proof." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ConstructiveProof.html