The Post correspondence problem is an undecidable decision problem that was introduced by Emil Post in 1946. Because it is simpler than the halting problem and the Entscheidungsproblem it is often used in proofs of undecidability.
Read more about Post Correspondence Problem: Definition of The Problem, Proof Sketch of Undecidability, Variants
Famous quotes containing the words post and/or problem:
“To the old saying that man built the house but woman made of it a “home” might be added the modern supplement that woman accepted cooking as a chore but man has made of it a recreation.”
—Emily Post (1873–1960)
“But a problem occurs about nothing. For that from which something is made is a cause of the thing made from it; and, necessarily, every cause contributes some assistance to the effect’s existence.”
—Anselm of Canterbury (1033–1109)