The Whisky Problem ------------------ ------ Summary: Needs some sort of Generalisation ------ ------ Definitions: p(0, 0) p(X, 0) -> p(h(X), 0) p(h(X), Y) -> p(X, s(Y)) ------ Theorem: forall y. p(0, y) ------ Comments: This is a proof from the domain of first order temporal logic. For it to go through the original conjecture needs to be generalised to: forall y, n. p(h^n(0), y) (where h^n means n applications of h - which is second order) or a new function h* needs to be introduced h*(0, X) = X h*(s(n), X) = h(h*(n, X)) and the conjecture generalised to forall y, n. p(h*(n, 0), y) ------ Source: Logics group at Liverpool. In particular Michael Fisher and Anatoli Degtyarev. Problem originally attributed to Regimantas Pliuskevicius.