 The solution that situation semantics offered for the puzzle of logically equivalents in attitude ascriptions encountered competition from the very start: state-of-affairs and infons looked suspiciously like structured propositions (see the entry  structured propositions).  Intensional versions of structured propositions had already been offered as remedies for the attitude ascription problem by Carnap 1947, Lewis 1972, Cresswell &amp; von Stechow 1982, and were also appealed to for the analysis of information structure and intonational meaning. The structured meanings of Carnap, Lewis, and Cresswell &amp; von Stechow are tree structures whose end nodes are intensions, rather than lexical items. They are thus objects that are independent of the vocabularies of particular languages, but are nevertheless hierarchically structured in the way sentences are. Differences between structured propositions in various frameworks and the state-of-affairs or infons of situation theory seem to largely boil down to foundational matters regarding the status of possibilia (see the entries on  possible objects  and possible worlds) and the nature of properties and relations (see  properties).