§4.5 BCK Games for LCM and Constructive Implication.
LCM: Markov Principle. (¬¬∃x.P(x)⇒∃x.P(x))
LCM: Weak Koenig's Lemma. (∀x.∀y.(P(x)∨Q(y))⇒(∀x.P(x)∨∀y.Q(y)))
Created by Mathematica (November 11, 2006)