Homogeneity (semantics)

In formal semantics, homogeneity is the phenomenon where plural expressions that seem to mean "all" negate to "none" rather than "not all". For example, the English sentence "Robin read the books" requires Robin to have read all of the books, while "Robin didn't read the books" requires her to have read none of them. Neither sentence is true if she read exactly half of the books. Homogeneity effects have been observed in a variety of languages including Japanese, Russian, and Hungarian. Semanticists have proposed a variety of explanations for homogeneity, often involving a combination of presupposition, plural quantification, and trivalent logics. Because analogous effects have been observed with conditionals and other modal expressions, some semanticists have proposed that these phenomena involve pluralities of possible worlds.