:: <math>\{X \,|\, \forall x (x \text{ is a boy} \to x \in X) \}</math>
This treatment of quantifiers has been essential in achieving a [[compositionality|compositional]] [[semantics]] for sentences containing quantifiers.<ref>{{cite [[Richardbook Montague|last1=Montague, |first1=Richard]]: |author-link1=Richard Montague |date=1974,'[|url=http://www.blackwellpublishing.com/content/BPL_Images/Content_store/Sample_chapter/9780631215417/Portner.pdf |chapter=The proper treatment of quantification in English]' |title=Philosophy, Language, and Artificial Intelligence |series=Studies in Cognitive Systems |volume=2
It has been proposed that ''all'' determiners{{emdash}}in every natural language{{emdash}}are conservative.<ref ([[Jon name=Barwise|Barwise]]and Cooper 1981)./> The expression ''only'' is not conservative. The following two sentences are not equivalent. But it is, in fact not common to analyze ''only'' as a [[determiner (linguistics)|determiner]]. Rather, it is standardly treated as a [[focus-sensitive]] [[adverb]].