The question of whether a solution to a given problem exists. The existence problem can be solved in the affirmative without actually finding a solution to the original problem. Such a demonstration is said to be nonconstructive, and is called a nonconstructive proof or an existence proof.
Existence Problem
See also
Constructive Proof, Enumeration Problem, Existence, Existence Theorem, Nonconstructive Proof, Picard's Existence Theorem, ProofExplore with Wolfram|Alpha
References
Gardner, M. The Sixth Book of Mathematical Games from Scientific American. Chicago, IL: University of Chicago Press, p. 22, 1984.Richman, F. "Existence Proofs." Amer. Math. Monthly 106, 303-308, 1999.Referenced on Wolfram|Alpha
Existence ProblemCite this as:
Weisstein, Eric W. "Existence Problem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ExistenceProblem.html