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Sentence/Name/Abbreviation/Substitute/Proxy/Geach: e.g. if "P" and "Q" are abbreviations of sentences and "A" and "B", the respective names of these sentences, then we could have a convention, by which "A > B" is the name (abbreviation) of the sentence "P > Q".
Autonymous/Carnap: the symbol ">" in "A > B", is used as a sign of itself, autonymous - (Geach per)
Conjunction/Sentence/Frege: "P u Q" is a phrase that is different from "p" and "q" individually - Mill: ditto: otherwise "a group of horses" would be the same as "a kind of horse" - but not: E.g. "Jim is convinced and his wife is unfaithful"- solution: "the fact that ..." is always to be split into a pair of statements.
Sentence / GeachVsAristoteles: it is a mistake to analyze complex sentences as a combination of atomic sentences.
Logic Matters Oxford 1972