  Tichý created a system of intensional logic very similar to that of Montague, beginning, in English, in Tichý 1971, with a detailed presentation in Tichý 1988. Unfortunately his work did not become widely known. Like Montague’s semantics, Tichý’s formal work is based on a type hierarchy with intensions mapping worlds to extensions at each type level, but it goes beyond Montague in certain respects. For one thing, intensions depend not only on worlds, but also on times. For another, in addition to intensions and extensions Tichý also considers constructions. The idea is that expressions determine intensions and extensions, and this itself is a formal process in which compound expressions act using the simpler expressions that go into their making; compositionality at the level of constructions, in other words. Using this formal machinery, “\(1+4\)” and “\(2+3\)” prescribe different constructions; their meaning is not simply captured by their intensional representation as discussed here.