These simpler propositions are called conjuncts . A conjunction is true if and only if both of its conjuncts are true . Thus, if either part of a conjunct is false, then the conjunction itself is false. There are two types of disjunctions, or two ways to interpret a disjunction. A exclusive disjunction is one which says either P or Q, but not both .
Logicians are interested in inclusive disjunctions.
Thus, for our purposes, a disjunction is true if and only if at least one of its disjuncts are true . This looks quite odd at first. And the only way that could be false is if some number could be less than two but not less that 4.