The Entscheidungsproblem is a problem posed by David Hilbert and Wilhelm Ackermann in 1928. It asks if there is an algorithm that outputs “yes” or “no” if an input statement is universally valid. It was proven to be impossible by Alonzo Church and Alan Turing in 1936.
Hilbert and Ackermann, leading mathematicians of the early 20th century, were keen to establish the verity of the Entscheidungsproblem, i.e. whether or not there was an algorithm that could determine the truth of any mathematical statement.