   Russell used the phrase “molecular proposition” for those propositions that are compounded using truth-function operators.  Examples would include, “F(a) &amp; R(a, b)” and “R(a, b) ∨ R(b, a)”. According to Russell, it is unnecessary to suppose that there exists any special sort of fact corresponding to molecular propositions; the truth-value of a molecular proposition could be entirely derivative on the truth-values of its constituents (PLA, 209). Hence, if “F(a) &amp; R(a,b)” is true, ultimately it is made true by two atomic facts, the fact that a has property F and the fact that a bears R to b, and not by a single conjunctive fact.