 The particle rules for a conjunction are the following: when a player \(\mathbf{X}\) (either P or O) states a conjunction, the other player \(\mathbf{Y}\) may challenge the conjunction by choosing one of the conjuncts (the left one \(L^{\land}\) or the right one \(R^{\land}\)) and requesting it (? in front of the chosen conjunct). The first player \(\mathbf{X}\) defends the conjunction by stating the requested conjunct.