|Addition: elementary arithmetic, which is usually characterized by associativity and commutativity and a neutral zero element.|
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Plus sign/ and / Addition / Frege: if you use "and" as in "Bunsen and Kirchhoff" then 1 and 1 and 1 is not equal to 3, but 1 - E.g. Gold and gold and gold is never anything other than gold - it follows: 1. if we consider the number as a summary of different, we get a accumulation, and that’s not the number - 2. a summary of the same: we always get the 1 as a result.
Die Grundlagen der Arithmetik Stuttgart 1987
Funktion, Begriff, Bedeutung Göttingen 1994
Logische Untersuchungen Göttingen 1993